Over the years we have provided countless custom knurled hardware pieces - below is a snapshot of a custom bolt we are working on producing for a customer that is intended to be hammered into a predrilled steel plate. We noticed that the spec calls out for diamond knurling but realized that probably won't work for the intended purpose, which is to keep the bolt from spinning after being inserted.

After discussing it with the factory engineers we suggested going with a straight knurl instead of the diamond knurl. The straight knurl would work better in keeping engagement. We put together these samples to allow our customer to test the idea before incorporating it fully into the production run. The production parts would be made using the same 41L40 steel material with a zinc plated finish.