Bearings, Gears & Power Transmission calculator
Precision Grinding Cost Calculator
Combine the parts in the grinding scope, the per-part grinding rate and the fixed setup cost into one lot total. The page then splits it across every part and across only the ground parts.
What this calculator does
- Total precision grinding cost, the cost per ground part, and the overage against the per-part target.
Formula used
- Ground parts = components in grinding scope × parts requiring precision grinding ÷ 100
- Variable grinding cost = components in scope × grinding cost per part × grinding share ÷ 100
- Total grinding cost = variable grinding cost + fixed setup and inspection cost
- Cost per ground part = total grinding cost ÷ ground parts; cost per part = total ÷ components
- Cost per ground part over target = cost per ground part − target cost per ground part
Inputs explained
- Components in Grinding Scope: Parts in the grinding scope for this lot, from the router.
- Precision Grinding Cost per Part: Quoted or actual grinding cost for one part, from the quote.
- Parts Requiring Precision Grinding: Share of the scope needing precision grinding, from the process plan.
- Fixed Setup and Inspection Cost: Setup and inspection charged once per grinding lot, from the quote.
- Target Cost per Ground Part: Cost per ground part the quote allows, from the estimate.
How to use the result
- Best suited to quoting a bearing race grinding lot, comparing grinding shares across lots, checking a per-ground-part cost target.
- Mixing rough and fine grinds in one scope hides the rates that drive each pass. The target is a per-part cost check, not a quote price; overhead and margin sit outside it.
Current U.S. benchmarks
- The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).
Common questions
- Why are there two cost per part figures? One divides the total by every part in scope, the other by the parts actually ground. The second is higher because fixed setup spreads over fewer parts, and it is the one to quote.
- What does the grinding share change? It sets how many parts receive grinding. A lower share cuts variable cost but pushes fixed setup onto fewer parts, so the per-ground-part cost can rise.
- Is the fixed setup cost really fixed? Per lot, yes. Setup and inspection are charged once whether the lot has 100 parts or 1,000, so the per-ground-part figure falls as the lot grows.
- Which target should I enter? The cost per ground part that the quote allows. Above it, reduce the share needing grinding, improve the rate, or spread setup over a larger lot.
Related guides
Last reviewed 2026-10-01.