This reply from a manufacturer, quote: '....specialising in small batch production sums it up...........
Mon, 15 Feb, 20:17 (2 days ago)
Sorry we only do stainless. We do not know anybody who makes normal steel bolts due to the plating problems nowadays.
If we made them we would have to retool, keep the swarf separate and minimum order would have to be in the several hundred
due to the amount of inserts (come in boxes of 10 at £15 each) (would need 5 boxes) plus 8 to 12 hours setup and tooling times required to retool a cnc and reprogram.
You need to find somebody who does it as a hobby on manual machines.
for Motalia Ltd