About · the founder
Built by a manufacturer.
For more than thirty years, Michael MacArthur has been part of the team at RobbJack, a precision carbide cutting-tool manufacturer that sells through industrial distributors. Precision Tolerance AI is the method he built there, on RobbJack's own pricing, quoting and order data, offered to the distributors and manufacturers who live with the same problems.
Michael MacArthur · founder The story
Thirty years of holding tolerance.
RobbJack makes solid carbide end mills, routers and slitting saws, and sells them through industrial distributors. In that business a tool is either in tolerance or it's scrap, and nobody argues with the gauge. Mike is RobbJack's President and has been part of the RobbJack team for more than three decades.
Pricing data never had a gauge. When material and tariff costs started moving faster than any price list could follow, Mike rebuilt RobbJack's pricing, quoting and order data with AI agents and a simple discipline: measure every record, let the person with authority rule on every open question, apply the ruling on a copy, and turn it into a check that runs forever.
It worked well enough that distributors and other manufacturers started asking how. Precision Tolerance AI is the answer: the same method, run for your company, by the person who built it.
— Michael MacArthur, founder · Placer County, California
Proof · measured at RobbJack
Five gauge blocks.
What the method did on RobbJack's own data, stated the only way we state client results: as percentages and counts, never dollars.
- 97% of purchase-order lines read correctly by AI. Blind test on 1,395 real purchase orders the AI had never seen: each line it read was graded against what RobbJack’s order desk entered. As of October 2026.
- 98% of repeat quotes reproduce the quote desk’s own price ladder. Share of RobbJack’s past repeat quotes where the quote engine produced the same price ladder the quote desk had quoted. As of October 2026.
- 20 automated pricing-rule checks run on every change. Count of automated checks on RobbJack’s pricing rules that run every time a price changes. As of October 2026.
- 92% of priced SKUs repriced to current material cost, with every SKU accounted for. Share of RobbJack’s priced SKUs whose price was rebuilt on its current material cost. As of October 2026.
- −75% quote-engine pricing error. Change in RobbJack’s quote-engine pricing error after the rebuild. As of October 2026.
- Measured at RobbJack and published with RobbJack’s written authorization, as percentages and counts only.
How it works
Measure. Rule. Fix. Guard.
- 01
Measure
Forensic scan
Every row of your item, price, cost and customer data checked against the rules a good price file obeys. Each defect pattern comes back as a count, a dollar estimate and real example rows.
See it in Margin X-Ray → - 02
Rule
Decision Cards
Each open question becomes a one-minute card for the person with authority: the recommendation, the impact, the options. Their ruling is recorded with who, when and their words.
See it in Decision Cards → - 03
Fix
Import files you load
Rulings are applied on a copy, never on your live system. You get ERP import files your own people review and load, and every change is proven with an independent read-back.
See it in The Glass Box → - 04
Guard
Checks that run forever
Every ruling becomes a check that runs every month. When costs move or someone keys a bad price, you hear about what changed, and only that.
See it in Replay 2026 →
Two companies
RobbJack proved it. It doesn't see your data.
Where the method was built
- A precision carbide cutting-tool manufacturer: solid carbide end mills, routers and slitting saws.
- Mike is its President.
- Its results appear here with its written authorization, as percentages and counts only.
Where your data lives
- A separate company with its own systems, accounts and AI workspace.
- Client data is never shared with RobbJack.
- We never share your data with RobbJack or anyone else, and we back that up with a written agreement.
We never share your data with RobbJack, and if you carry competing cutting-tool lines, Blind Export lets us work without even knowing whose they are. Read the promise · Open Blind Export
Next step
Put your data on the surface plate.
Run the Margin X-Ray on a sample file or your own. It runs entirely in your browser.
Quick question first? AI