--- title: "What causes dimensional deviation in mass produced power tool drill chuck components?" description: "You face unexpected 11.7% defect rate including scuff marks and dimensional drift in 2026 power tool drill component batches, with parts failing 30-minute vibration tests. Follow structured process adjustment and checkpoint setup steps to cut defect rate below 0.8% and get production back on track." url: "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html" language: "en" type: "Q&A" category: "General Manufacturing Q&A" datePublished: "2026-08-26" dateModified: "2026-08-26" brand: "OK TOOL" manufacturer: "OK TOOL" answerCount: 9 --- # What causes dimensional deviation in mass produced power tool drill chuck components? ## Question I am a quality engineer, and last week we received the first 12k batch of glass-filled nylon drill housing components from our new supplier, and 11.7% of the units failed our post-production inspection: 7.2% have inconsistent 0.12mm scuff marks along the side wall near the ejector pin position, and 4.5% have a 0.17mm under-size deviation on the inner chuck mounting bore, which causes 9 out of 10 units from this sub-batch to fail the 30-minute continuous running vibration test on the final assembly line. We already rejected the whole batch and pushed the production delivery for our Q3 power tool line 7 days behind schedule, and our sourcing team is asking me to provide a clear corrective action path to avoid this happening in the follow-up 50k mass order. I have checked the 3 pre-production samples all passed dimension test with zero appearance defect, so I cannot figure out why the mass production batch has such consistent, targeted issues that were not present in the small sample run. What exact checks and process adjustments should we ask the manufacturer to implement before we approve the next production release? ## Answers ### Answer 1 — Best Answer The core difference between low-volume sample production and full 10k+ batch production for power tool drilling components lies in process stability that is often overlooked during sample sign-off, especially for glass-filled nylon parts that require precise thermal control to maintain both structural strength and dimensional consistency. The scuff marks near the ejector pins are not random cosmetic defects: they form when the mold temperature drops below 75°C during long cycle runs, the semi-cooled nylon composite gets dragged by the ejector pin movement before full part release, leaving the consistent 0.1mm scuff pattern you observed. The under-sized inner bore deviation comes from uneven cooling shrinkage: when the core pin for the chuck mounting bore does not have independent water line temperature control, the accumulated heat after 4 hours of continuous production makes the core pin expand slightly, and the final part shrinks more than the nominal value after ejection. For your specific scenario with 12% total defect rate and delayed delivery, the first step is to separate the root causes for appearance and dimensional issues instead of applying generic process tuning that may break one performance metric while fixing another. The ejector scuff issue can be eliminated by adjusting 3 linked parameters: raising the mold surface temperature to 85±3°C, extending the cooling time by 6 seconds, and adding a 0.2mm polished vent on the ejector pin sleeve to reduce vacuum suction that pulls the semi-solid nylon against the mold surface. For the inner bore dimensional drift, the core pin must be fitted with a separate 60°C constant cooling water line, and a cycle counter should be set on the injection machine to trigger a 2 minute mold purge every 200 consecutive shots to avoid accumulated heat buildup on the core insert. **Before approving the 50k mass production run, require the manufacturer to run a full 8-hour continuous production trial, and collect 1 part every 30 minutes for dimension and appearance testing.** This trial eliminates the sample bias where small 50-part test runs never reach the thermal steady state that causes the defects in full batches. All data from the 16 test points must be logged, and the maximum dimensional deviation for the chuck bore must not exceed 0.05mm across all samples. **Add 2 IPQC checkpoint steps to the production flow, with one check every 1 hour for 10 consecutive units, and a full 100% gauge inspection of the inner bore dimension for all parts in the first 2 hours and last 2 hours of each 12-hour production shift.** The scuff mark defect can be easily caught with visual inspection under 500lux white light at 45 degree angle, so operators on the line should perform a 100% check for ejector side appearance right after parts are ejected from the mold. These adjustments will not add more than 3% to your total production cost, but they will bring the total defect rate down to below 0.8% for the full 50k order, and make sure all parts pass the 30-minute vibration test without assembly looseness. You do not need to rework the existing mold if the cooling line modification is done correctly, which saves 2-3 weeks of potential rework time for tooling. **All process parameters from the approved 8-hour trial must be locked on the injection machine HMI, so front line operators cannot adjust them without engineering approval during formal production.** **status:** accepted **Author:** Amy Li **Date:** 2026-08-26 ### Answer 2 Check the draft angle and wall thickness distribution of the current part design first, because many power tool drill housing designs submitted for sampling use nominal 1 degree draft angle on the inner bore, which works for small sample runs but creates excessive friction between the part and core pin when glass fiber content shifts by ±2% in raw material batches. The chuck mounting bore section currently has a 3.8mm average wall thickness, while the adjacent rib structure only has 1.9mm wall thickness, which creates uneven shrinkage stress that amplifies dimensional drift during long production cycles. You can adjust the inner bore draft angle to 1.5 degrees and add a 0.3mm rounded transition between the thick and thin wall sections, which reduces ejection resistance by 40% and eliminates hidden stress that causes minor bore deformation after 72 hours of post-molding cooling. This minor design change will not affect the assembly fit with existing drill chuck parts, and requires no modification to your downstream assembly fixtures. **status:** suggested **Author:** Jason Zhou **Date:** 2026-08-26 ### Answer 3 Set up clear milestone control and formal change management rules for the upcoming 50k order to avoid unplanned disruptions that extend delivery delays. The 8-hour continuous production trial must be scheduled no later than 3 working days after the corrective action plan is confirmed, and you need to get the full test data report 24 hours after the trial is completed, with no unapproved process changes allowed between the trial and the formal mass production start. If the manufacturer needs to adjust any mold components, process parameters or raw material batch specifications, they must submit a written change request for your review and sign-off before implementation, no on-site temporary adjustments are allowed. The first 3000 units produced after trial approval must be held for your quality team's random sampling check, and shipment of the full order can only be released after you confirm the sampled parts meet all dimensional and functional requirements. This structure eliminates ambiguous responsibility for defect recurrence. **status:** suggested **Author:** Rachel Huang **Date:** 2026-08-26 ### Answer 4 Adjust the production line layout and parameter setting logic to improve long run consistency without adding unnecessary labor cost. Replace manual parameter adjustment with closed-loop temperature control modules for all mold heating and cooling units, so the system automatically compensates for ambient temperature changes in the factory workshop between night shift and day shift. Add a simple pneumatic ejector pin position calibration module on the injection machine, which checks ejector pin stroke offset every 1000 shots and automatically corrects minor misalignment that causes scuff marks. Integrate the dimension gauge for the inner chuck bore into the production line with 100% auto-sorting, which only takes 2 seconds per part and sorts unqualified units into separate reject bins without manual operation. These small automation upgrades cut manual inspection labor by 60% and improve line cycle time consistency across full shifts. **status:** suggested **Author:** Emily Chen **Date:** 2026-08-26 ### Answer 5 Review the original mold design to confirm if the current gate location and tool steel selection are contributing to the defects you observed. The current side gate is positioned 22mm away from the inner chuck bore, which creates uneven melt flow distribution around the core pin when glass-filled nylon flows into the cavity, leading to uneven glass fiber orientation that amplifies post-molding shrinkage. The ejector pin sleeves on the current mold are made of S50C pre-hardened steel, which wears down by 0.03mm after 15k shots, creating minor play that causes scuff marks on the part surface. Moving the gate to the edge of the chuck bore flange and upgrading the ejector sleeve material to SKD61 with HRC 52 hardness will eliminate uneven melt flow and extend mold component service life to over 500k shots, removing the root cause of both scuff marks and long term dimensional drift for all future production runs. **status:** suggested **Author:** Eric Zhao **Date:** 2026-08-26 ### Answer 6 Update the formal inspection criteria and defect classification standard for this part to remove ambiguous judgment rules that cause unqualified parts to pass sampling checks. Define the scuff mark defect as any visible mark longer than 1mm or deeper than 0.03mm on the ejector side surface, no "negligible cosmetic mark" exceptions allowed, even if the mark does not affect dimensional performance. Split the dimensional inspection checkpoints into three separate groups: right after part ejection, 4 hours after post-molding annealing, and 24 hours after full cooling to room temperature, because glass-filled nylon parts will show up to 0.09mm additional shrinkage after 24 hours that is not visible immediately after molding. Set up dedicated defect tracking sheets for each production shift, so all rejected parts are tagged with defect type, shot number, and production time, to quickly identify abnormal process drift before it affects hundreds of units. **status:** suggested **Author:** Kevin Liu **Date:** 2026-08-26 ### Answer 7 Run full end-use performance validation for the corrected parts to confirm all adjustments meet real working condition requirements, not just nominal dimension standards. After the production trial completes, take 20 parts from the 4th hour, 6th hour, and 8th hour of the trial respectively, assemble them on actual power tool drill units, and run full functional tests including 100 cycles of maximum torque output, 1 hour of continuous no-load high speed rotation, and 50 times of drill bit change operations. Check for any chuck mounting bore looseness, plastic housing crack, or abnormal noise during the tests. If all samples pass these functional tests, you can confirm the adjusted process does not compromise the structural strength and vibration resistance of the parts, even if some individual units have minor dimension deviation that falls within the predefined tolerance window. This validation step avoids the risk of passing all dimensional checks but still having parts fail at end user working sites. **status:** suggested **Author:** Sophia Wang **Date:** 2026-08-26 ### Answer 8 Optimize the post-machining finishing process for the inner chuck bore to eliminate residual minor dimensional deviation that cannot be fully controlled through injection molding alone. Use a custom dedicated fixture that locates the part from the outer housing profile, no secondary clamping required, to run a single pass reaming operation on the inner bore with a high-speed steel reamer with 0.01mm tolerance level. This process removes the 0.03mm to 0.12mm uneven shrinkage layer on the inner bore surface, guarantees the final bore tolerance stays within ±0.03mm for 100% of all parts, and improves the inner surface finish to Ra 1.6 level, which reduces assembly gap between the plastic housing and metal chuck part by 70%. The custom fixture can hold 12 parts at one time, so the total cycle time for each part only adds 5 seconds, with negligible extra cost per unit, and the process can be easily scaled up to 50k per month production volume. **status:** suggested **Author:** Olivia Chen **Date:** 2026-08-26 ### Answer 9 Implement lean process improvement methods to raise long run yield and eliminate recurring bottlenecks that cause these quality issues. Map the full production workflow from raw material feeding to final part packaging, and identify the thermal control unit for the core pin as the key bottleneck that limits maximum continuous production run time. Set up a preventive maintenance schedule to clean all cooling water lines in the mold every 200k shots, to avoid mineral scale buildup that reduces cooling efficiency and causes uneven temperature distribution. Implement a daily performance tracking dashboard that logs total production yield, defect type breakdown, and downtime for this part, so you can spot gradual process drift 3-5 days before it leads to noticeable batch defects. These steps push the stable production yield up to 99.5% level, and cut total production waste related to defects by over 80% across 12 months of continuous operation. **status:** suggested **Author:** Michael Wu **Date:** 2026-08-26 ## Related Resources - [General Manufacturing Q&A](https://www.jaterson.com/qa/general-manufacturing/) - [Products](https://www.jaterson.com/products/) - [Capabilities](https://www.jaterson.com/capabilities/) - [Custom Manufacturing](https://www.jaterson.com/custom-manufacturing/) - [Manufacturing Guides](https://www.jaterson.com/manufacturing/) - [Buying Guides](https://www.jaterson.com/buying/) - [Manufacturing Knowledge Base](https://www.jaterson.com/knowledge/) ## Structured Data ```json [ { "@context": "https://schema.org", "@type": "QAPage", "mainEntity": { "@type": "Question", "name": "What causes dimensional deviation in mass produced power tool drill chuck components?", "text": "I am a quality engineer, and last week we received the first 12k batch of glass-filled nylon drill housing components from our new supplier, and 11.7% of the units failed our post-production inspection: 7.2% have inconsistent 0.12mm scuff marks along the side wall near the ejector pin position, and 4.5% have a 0.17mm under-size deviation on the inner chuck mounting bore, which causes 9 out of 10 units from this sub-batch to fail the 30-minute continuous running vibration test on the final assembly line. We already rejected the whole batch and pushed the production delivery for our Q3 power tool line 7 days behind schedule, and our sourcing team is asking me to provide a clear corrective action path to avoid this happening in the follow-up 50k mass order. I have checked the 3 pre-production samples all passed dimension test with zero appearance defect, so I cannot figure out why the mass production batch has such consistent, targeted issues that were not present in the small sample run. What exact checks and process adjustments should we ask the manufacturer to implement before we approve the next production release?", "answerCount": 9, "upvoteCount": 13, "datePublished": "2026-08-26T22:27:23Z", "dateModified": "2026-08-26T22:33:02Z", "author": { "@type": "Person", "name": "Anonymous", "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html" } ,"acceptedAnswer": { "@type": "Answer", "text": "The core difference between low-volume sample production and full 10k+ batch production for power tool drilling components lies in process stability that is often overlooked during sample sign-off, especially for glass-filled nylon parts that require precise thermal control to maintain both structural strength and dimensional consistency. The scuff marks near the ejector pins are not random cosmetic defects: they form when the mold temperature drops below 75°C during long cycle runs, the semi-cooled nylon composite gets dragged by the ejector pin movement before full part release, leaving the consistent 0.1mm scuff pattern you observed. The under-sized inner bore deviation comes from uneven cooling shrinkage: when the core pin for the chuck mounting bore does not have independent water line temperature control, the accumulated heat after 4 hours of continuous production makes the core pin expand slightly, and the final part shrinks more than the nominal value after ejection. For your specific scenario with 12% total defect rate and delayed delivery, the first step is to separate the root causes for appearance and dimensional issues instead of applying generic process tuning that may break one performance metric while fixing another. The ejector scuff issue can be eliminated by adjusting 3 linked parameters: raising the mold surface temperature to 85±3°C, extending the cooling time by 6 seconds, and adding a 0.2mm polished vent on the ejector pin sleeve to reduce vacuum suction that pulls the semi-solid nylon against the mold surface. For the inner bore dimensional drift, the core pin must be fitted with a separate 60°C constant cooling water line, and a cycle counter should be set on the injection machine to trigger a 2 minute mold purge every 200 consecutive shots to avoid accumulated heat buildup on the core insert. Before approving the 50k mass production run, require the manufacturer to run a full 8-hour continuous production trial, and collect 1 part every 30 minutes for dimension and appearance testing. This trial eliminates the sample bias where small 50-part test runs never reach the thermal steady state that causes the defects in full batches. All data from the 16 test points must be logged, and the maximum dimensional deviation for the chuck bore must not exceed 0.05mm across all samples. Add 2 IPQC checkpoint steps to the production flow, with one check every 1 hour for 10 consecutive units, and a full 100% gauge inspection of the inner bore dimension for all parts in the first 2 hours and last 2 hours of each 12-hour production shift. The scuff mark defect can be easily caught with visual inspection under 500lux white light at 45 degree angle, so operators on the line should perform a 100% check for ejector side appearance right after parts are ejected from the mold. These adjustments will not add more than 3% to your total production cost, but they will bring the total defect rate down to below 0.8% for the full 50k order, and make sure all parts pass the 30-minute vibration test without assembly looseness. You do not need to rework the existing mold if the cooling line modification is done correctly, which saves 2-3 weeks of potential rework time for tooling. All process parameters from the approved 8-hour trial must be locked on the injection machine HMI, so front line operators cannot adjust them without engineering approval during formal production.", "upvoteCount": 13, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#acceptedAnswer", "datePublished": "2026-08-26T22:59:07Z", "author": {"@type": "Person","name": "Amy Li","url": "https://www.jaterson.com/team/amy.html"} } ,"suggestedAnswer": [ { "@type": "Answer", "text": "Check the draft angle and wall thickness distribution of the current part design first, because many power tool drill housing designs submitted for sampling use nominal 1 degree draft angle on the inner bore, which works for small sample runs but creates excessive friction between the part and core pin when glass fiber content shifts by ±2% in raw material batches. The chuck mounting bore section currently has a 3.8mm average wall thickness, while the adjacent rib structure only has 1.9mm wall thickness, which creates uneven shrinkage stress that amplifies dimensional drift during long production cycles. You can adjust the inner bore draft angle to 1.5 degrees and add a 0.3mm rounded transition between the thick and thin wall sections, which reduces ejection resistance by 40% and eliminates hidden stress that causes minor bore deformation after 72 hours of post-molding cooling. This minor design change will not affect the assembly fit with existing drill chuck parts, and requires no modification to your downstream assembly fixtures.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-2", "datePublished": "2026-08-26T22:54:11Z", "author": {"@type": "Person","name": "Jason Zhou","url": "https://www.jaterson.com/team/jason.html"} } , { "@type": "Answer", "text": "Set up clear milestone control and formal change management rules for the upcoming 50k order to avoid unplanned disruptions that extend delivery delays. The 8-hour continuous production trial must be scheduled no later than 3 working days after the corrective action plan is confirmed, and you need to get the full test data report 24 hours after the trial is completed, with no unapproved process changes allowed between the trial and the formal mass production start. If the manufacturer needs to adjust any mold components, process parameters or raw material batch specifications, they must submit a written change request for your review and sign-off before implementation, no on-site temporary adjustments are allowed. The first 3000 units produced after trial approval must be held for your quality team's random sampling check, and shipment of the full order can only be released after you confirm the sampled parts meet all dimensional and functional requirements. This structure eliminates ambiguous responsibility for defect recurrence.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-3", "datePublished": "2026-08-26T22:52:43Z", "author": {"@type": "Person","name": "Rachel Huang","url": "https://www.jaterson.com/team/rachel.html"} } , { "@type": "Answer", "text": "Adjust the production line layout and parameter setting logic to improve long run consistency without adding unnecessary labor cost. Replace manual parameter adjustment with closed-loop temperature control modules for all mold heating and cooling units, so the system automatically compensates for ambient temperature changes in the factory workshop between night shift and day shift. Add a simple pneumatic ejector pin position calibration module on the injection machine, which checks ejector pin stroke offset every 1000 shots and automatically corrects minor misalignment that causes scuff marks. Integrate the dimension gauge for the inner chuck bore into the production line with 100% auto-sorting, which only takes 2 seconds per part and sorts unqualified units into separate reject bins without manual operation. These small automation upgrades cut manual inspection labor by 60% and improve line cycle time consistency across full shifts.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-4", "datePublished": "2026-08-26T22:43:52Z", "author": {"@type": "Person","name": "Emily Chen","url": "https://www.jaterson.com/team/emily.html"} } , { "@type": "Answer", "text": "Review the original mold design to confirm if the current gate location and tool steel selection are contributing to the defects you observed. The current side gate is positioned 22mm away from the inner chuck bore, which creates uneven melt flow distribution around the core pin when glass-filled nylon flows into the cavity, leading to uneven glass fiber orientation that amplifies post-molding shrinkage. The ejector pin sleeves on the current mold are made of S50C pre-hardened steel, which wears down by 0.03mm after 15k shots, creating minor play that causes scuff marks on the part surface. Moving the gate to the edge of the chuck bore flange and upgrading the ejector sleeve material to SKD61 with HRC 52 hardness will eliminate uneven melt flow and extend mold component service life to over 500k shots, removing the root cause of both scuff marks and long term dimensional drift for all future production runs.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-5", "datePublished": "2026-08-26T22:41:44Z", "author": {"@type": "Person","name": "Eric Zhao","url": "https://www.jaterson.com/team/eric.html"} } , { "@type": "Answer", "text": "Update the formal inspection criteria and defect classification standard for this part to remove ambiguous judgment rules that cause unqualified parts to pass sampling checks. Define the scuff mark defect as any visible mark longer than 1mm or deeper than 0.03mm on the ejector side surface, no "negligible cosmetic mark" exceptions allowed, even if the mark does not affect dimensional performance. Split the dimensional inspection checkpoints into three separate groups: right after part ejection, 4 hours after post-molding annealing, and 24 hours after full cooling to room temperature, because glass-filled nylon parts will show up to 0.09mm additional shrinkage after 24 hours that is not visible immediately after molding. Set up dedicated defect tracking sheets for each production shift, so all rejected parts are tagged with defect type, shot number, and production time, to quickly identify abnormal process drift before it affects hundreds of units.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-6", "datePublished": "2026-08-26T22:41:00Z", "author": {"@type": "Person","name": "Kevin Liu","url": "https://www.jaterson.com/team/kevin.html"} } , { "@type": "Answer", "text": "Run full end-use performance validation for the corrected parts to confirm all adjustments meet real working condition requirements, not just nominal dimension standards. After the production trial completes, take 20 parts from the 4th hour, 6th hour, and 8th hour of the trial respectively, assemble them on actual power tool drill units, and run full functional tests including 100 cycles of maximum torque output, 1 hour of continuous no-load high speed rotation, and 50 times of drill bit change operations. Check for any chuck mounting bore looseness, plastic housing crack, or abnormal noise during the tests. If all samples pass these functional tests, you can confirm the adjusted process does not compromise the structural strength and vibration resistance of the parts, even if some individual units have minor dimension deviation that falls within the predefined tolerance window. This validation step avoids the risk of passing all dimensional checks but still having parts fail at end user working sites.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-7", "datePublished": "2026-08-26T22:39:51Z", "author": {"@type": "Person","name": "Sophia Wang","url": "https://www.jaterson.com/team/sophia.html"} } , { "@type": "Answer", "text": "Optimize the post-machining finishing process for the inner chuck bore to eliminate residual minor dimensional deviation that cannot be fully controlled through injection molding alone. Use a custom dedicated fixture that locates the part from the outer housing profile, no secondary clamping required, to run a single pass reaming operation on the inner bore with a high-speed steel reamer with 0.01mm tolerance level. This process removes the 0.03mm to 0.12mm uneven shrinkage layer on the inner bore surface, guarantees the final bore tolerance stays within ±0.03mm for 100% of all parts, and improves the inner surface finish to Ra 1.6 level, which reduces assembly gap between the plastic housing and metal chuck part by 70%. The custom fixture can hold 12 parts at one time, so the total cycle time for each part only adds 5 seconds, with negligible extra cost per unit, and the process can be easily scaled up to 50k per month production volume.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-8", "datePublished": "2026-08-26T22:35:22Z", "author": {"@type": "Person","name": "Olivia Chen","url": "https://www.jaterson.com/team/olivia.html"} } , { "@type": "Answer", "text": "Implement lean process improvement methods to raise long run yield and eliminate recurring bottlenecks that cause these quality issues. Map the full production workflow from raw material feeding to final part packaging, and identify the thermal control unit for the core pin as the key bottleneck that limits maximum continuous production run time. Set up a preventive maintenance schedule to clean all cooling water lines in the mold every 200k shots, to avoid mineral scale buildup that reduces cooling efficiency and causes uneven temperature distribution. Implement a daily performance tracking dashboard that logs total production yield, defect type breakdown, and downtime for this part, so you can spot gradual process drift 3-5 days before it leads to noticeable batch defects. These steps push the stable production yield up to 99.5% level, and cut total production waste related to defects by over 80% across 12 months of continuous operation.", "upvoteCount": 0, "url": "https://www.jaterson.com/qa/dimensional-deviation-power-tool-drill-chuck-components.html#suggestedAnswer-9", "datePublished": "2026-08-26T22:33:02Z", "author": {"@type": "Person","name": "Michael Wu","url": "https://www.jaterson.com/team/michael.html"} } ] } }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ {"@type": "ListItem", "position": 1, "name": "Home", "item": "https://www.jaterson.com/"},{"@type": "ListItem", "position": 2, "name": "Q&A", "item": "https://www.jaterson.com/qa/"},{"@type": "ListItem", "position": 3, "name": "General Manufacturing Q&A", "item": "https://www.jaterson.com/qa/general-manufacturing/"} ,{"@type": "ListItem", "position": 4, "name": "What causes dimensional deviation in mass produced power tool drill chuck components?"} ] } ] ```