# Gear Grinding Cost Per Part: How Gear Manufacturers Estimate It > Source: https://netray.co/resources/gear-grinding-cost-per-part-estimating > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Knowledge Base ## Short answer Gear grinding cost per part for continuous generating and profile grinding: cycle time, wheel and dresser cost, stock removal, setup and rework to price jobs right. ## Category ai-automation ## Content **Intro:** Gear grinding cost per part is the machine rate times cycle time, plus wheel and dresser wear, setup spread across the lot, and the cost of rework and scrap when grinding burn or leftover distortion shows up. Continuous generating grinders (Reishauer style) are fast on higher volumes, while profile grinders handle large, internal and low-volume gears with longer cycles. Estimating well means knowing the stock to be removed, the number of passes, the dressing interval and the lot size, rather than using a flat hourly rate on a guessed time. **Sections:** #### Choose the Grinding Method First **Body:** The grinding method sets the cost model. Continuous generating grinding with a threaded wheel is efficient for small and mid-size external gears in volume, with short cycle times and a long setup. Profile grinding with a form wheel suits larger gears, internals in some machine types and low-volume or modified profiles, and takes longer per tooth gap. Some shops also hone or lap after grinding for noise-critical drives. Each method has its own machine rate, wheel type (vitrified, dressable or CBN plated), dresser cost and programming time. Pick the method from the drawing and the lot size, then apply that machine's actual rate rather than a blended shop rate. #### Estimate Stock Removal and Cycle Time **Body:** Cycle time follows stock. Check the hobbed (pre-heat-treat) tooth thickness, the expected growth or shrink from carburizing, and the finished tooth thickness to find stock per flank. Roughing and finishing passes, feed rates and the number of teeth drive time, and large gears with many teeth multiply it. Do not forget indexing and in-process probing, on-machine measurement and loading time. Where the shop has run the part family before, use the recorded cycle and the measured stock, not the programmed time. **Bullets:** - Pre-grind tooth thickness and expected heat treat movement - Number of teeth, face width and helix angle - Rough and finish passes plus spark-out - Load, unload, probe and tooth-index time #### Wheel, Dresser and Consumable Cost **Body:** Grinding wheels and diamond dressers are a real per-part cost. Conventional wheels are dressed back repeatedly and wear down, so cost is wheel price divided by the parts made per wheel life, plus dresser wear every dress. CBN wheels carry a higher price and a longer life, which changes the math at volume. Track dress amount, dress interval, and parts per wheel in the ERP or the machine log. If you price wheels as a lump overhead, a high-mix job with frequent re-dressing will look more profitable on paper than it is. #### Grinding Burn, Rework and Scrap Allowance **Body:** Grinding too aggressively can temper the case surface and leave grinding burn, which shows up on a temper etch (nital etch) inspection. Burn causes scrap or rework and, on aerospace or wind work, can mean a rejected lot. Include a scrap allowance based on your history for that material and heat treat, and include etch inspection time if the print calls for it. Heat treat distortion that exceeds the available stock also lands here. Quote a realistic yield rather than a hopeful one, and keep a record of scrap by part number so the next estimate uses fact instead of memory. #### Using ERP History and AI to Price Grinding Faster **Body:** Most gear shops have the data in the ERP but cannot find it quickly: actual run hours by operation, scrap by reason code and lot size. A private AI layer over that data can find similar gears by module, tooth count, material and accuracy grade and show actual grind cycles and yields side by side, then draft the grinding line for estimator review. It is least useful when you grind only a few part families and the estimator already knows them, or when production hours are not booked consistently, because the AI can only reflect the data it reads. **Cta:** Ask Netray how to surface actual grinding cycles, wheel life and yield by part family from your ERP, privately and read-only. **Faq:** #### How do you calculate gear grinding cost per part? **Answer:** Take the machine hourly rate times cycle time per part, add wheel and dresser wear per part, add setup hours divided by lot size, and add an allowance for scrap and rework. Use the actual machine rate and recorded cycle for the part family where you have it, and add inspection time if burn etch or full gear checks are required. #### Is gear grinding always necessary after heat treat? **Answer:** No. Many drive gears at moderate accuracy grades are hobbed or shaved and then hardened, with acceptable results. Grinding is needed when the print demands tight accuracy after heat treat or low noise. Check the drawing accuracy grade and customer requirements before adding a grind operation to the quote. #### What causes grinding burn on gears? **Answer:** Excess heat at the contact zone from aggressive feeds, a glazed or poorly dressed wheel, or too little coolant. It can temper the case and weaken the tooth surface. It is checked with a temper etch inspection. Process control, wheel dressing discipline and recorded parameters reduce it. ## Related Slugs - how-to-estimate-cost-of-a-custom-gear - heat-treatment-and-testing-costs-in-forging-quotes - gross-margin-analysis-manufacturing - heat-treat-distortion-gear-scrap-how-to-reduce ## Search terms gear grinding cost per part, gear grinding cost, continuous generating grinding cost, gear profile grinding estimate, gear grinding burn temper etch, gear grinding cycle time --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json