[pbd1971]

Lifted from a suppliers website.............

Tool Steel O1 is a medium alloyed oil hardening steel with excellent cutting force and toughness, the excellent dimensional stability reduces distortion and the possibility of cracking during heat treatment.

Supplied in the annealed condition, the precision tolerances minimise additional costly tool room machining.

Ground Flat Stock provides toolmakers with a decarburization free surface, plus a high wear resistance after heat treatment, making it ideal for a multitude of uses and applications: dies, press tools, punches, gauges, cams, jigs, machine knives and marking devices.
Hardness as supplied: 229 Brinell max
Tensile Strength: 45 Tons / sq. in.

Table of Equivalent specifications:

AISI Werk. No. AFNOR British Spec.
O1 1.2510 95 MCWV5 BS4659 BO1

I have 8 holes to tap in 6 plates so that's just 48 holes to do. I will be using the rigid tapping cycle on the mill. I am not chasing time on this job, just need to make sure i don't break the taps so quite happy to run a slower spindle speed if that's what's required.

Thanks

[PixMan]

Thanks for providing the details.

I have the Titex-Prototyp "TEC+CCS 10.2" software installed on my PC, so I ran it for you using all your data. I went with the tighter-tolerance 6G taps to help assure in-tolerance holes after heat-treatment.

First up is the premium roll form tap, a Protodyn S ECO Plus. Note the number of holes predicted per tap. It's a PM (powdered metal) TiCN-coated tap.



Next is the premium spiral flute tap, Paradur ECO-HT with THL (hard-lube) coating. It's also a HSS-Co PM tap.



For the lower number of holes and the fact that you'll be heat-treating the parts after machining, I lean toward the spiral flute tap as it's more-likely going to cut to size. A form tapped hole might have a little more shrinkage at heat treat.

It's list prices in US dollars that are showing. You'd have to contract a distributor in the UK for your pricing.

[pbd1971]

Thanks for the help and advise, managed to get through this job without any major trauma.