A gun drill coating name identifies a supplied surface treatment, not the whole tool. If the carbide, grind or previous service also changes, the comparison concerns a different tool package rather than an isolated coating effect.
What the published options establish
botek’s coating page lists TiN, TiCN, ALTiN, TiAlN and combination coatings. Its German counterpart gives the corresponding service options. The supplier also offers recoating in connection with regrinding.
The pages claim benefits in life, productivity and chip flow, but do not provide a controlled alloy-specific trial or a quantitative life multiplier. Their list can establish whether a coating service is offered. It cannot establish which coating is best for an unspecified bore.
Define the comparison before cutting
Retain the complete tool designation, carbide/body construction, cutting and peripheral geometry, coating identity and service state. Describe what is intended to differ between the two trial groups and what remains comparable.
For example, a new coated tool and a reground uncoated tool differ in more than coating. Recording only “coated versus uncoated” would conceal the service history. If a proposed trial changes several features deliberately, report it as a tool-package comparison and keep those features visible.
Use the same endpoint
Define the inspected output and the condition that ends each interval. More attempted holes is a different result from more accepted holes. A trial also needs material condition, hole geometry, guidance, fluid arrangement and cutting inputs alongside the actual bore observations.
An assumed result of 120 attempts and 100 acceptances is not directly comparable with another result reported only as 110 attempts. The missing acceptance count must remain missing. Neither the coating name nor an attractive average cutting time supplies it.
Recoating belongs to a service event
A reground and recoated tool should receive a new production interval attached to its physical identity. Record which geometry was serviced and the returned coating state before comparing its next results with those of a new tool.
The interval diagram below is an editorial record map, not a measured coating trial. Use the cost calculator with actual charges and accepted output after the scope is defined. Continue to regrinding for the returned geometry or lifecycle management to keep successive intervals separate. Those records make the eventual coating comparison assessable without assigning a winner from a service list.
Revision note
October 8, 2026: revised the technical explanation and connected reading after source review. Original publication date and URL retained.
