Sorby Tools - Are They All HSS?

[Allan Wright]

I obtained a collection of 8 Sorby tools with my lathe. None of them have HSS on the tool steel marked anywhere. They seem pretty tough to grind (I re-profiled a scraper) but the bowl gouge will turn blue fairly easily when sharpening. The bowl gouge also cuts very nicely for the first 2-3 passes when it has a nice bur on it then it quickly dulls. The tools I believe were purchased about 10 years ago. Would tools of this vintage be made from non-HSS? If they were HSS would they have been marked as such back then?

I'm just trying to figure out if I'm expecting too much from an excellent tool, or if I possibly have merely a good tool?

[Thom Sturgill]

In today's market, I would rate Sorby as good or maybe very good, but not excellent. I would reserve that for D-way and Thompson and a few others. I have heard claims that Sorby uses zone hardening (rather than oven hardening) and only the ench inch or so is hardened. I've only been turning for seven years, so I cannot address the historical aspect, but I do not believe all of my Sorby's are marked.

[Dale Miner]

I have a few vintage Sorby tools that are carbon steel.

The Sorby tools that are high speed steel are marked as such to the best of my knowledge. The marking is usually faint and may be worn away.

The spark from carbon steel when grinding is quite a bit different than hss. Carbon steel grinding sparks have an almost sparkler look to them. High speed steel sparks are much less dramatic and have an orange/red look to them with little secondary burst.

Both carbon and hss will turn blue when ground aggresively or with a dull wheel. Carbon steel will lose temper if it turns blue, hss temper will be relatively unaffected.

[Allan Wright]

Thanks for the advice. I'll bring the tools to my turning club and have one of the veterans sharpen it and tell me if I have HSS sparks or carbon steel sparks.

[Geoff Whaling]

AS Dale says have a look at https://en.wikipedia.org/wiki/Spark_testing & https://www.youtube.com/watch?v=Yq2FwCn3qFA & https://www.youtube.com/watch?v=7PWCh6fdXdw or search "Spark Testing" in Google.

[Allan Wright]

Your suggested search led me to this excellent article: http://woodturninglearn.net/articles/ToolSteel.pdf

I thought I would share it in case someone else searches this topic and finds this thread.

Thanks!
Allan

[Geoff Whaling]

Glad I could help, thank you for sharing your find. I have not seen that article by Alan Lacer but it clearly shows what we are talking about with turning tools.