Could be “drill rod”, aka yankee silver steel.

On 24 October 2025 at 07:18 Fulmen Said:

Could be “drill rod”, aka yankee silver steel.

I agree!  99% certain he’s using Drill Rod, what we in the UK call Silver Steel.   At one point he files it, then finishes by simply plunging the red-hot item into oil.  That’s not HSS.

HSS is carefully formulated for toughness and to stay hard up to red-heat.   Depends on the alloy mix plus a very elaborate series of heat-treatments lasting several hours.   Temperatures and soak times are critical and three or four precision ovens are needed because  the steel can’t be allowed to cool between stages.  Unlikely that the specialised kit needed to heat treat HSS will be found outside a factory.  And having the ovens isn’t enough!  As Bazyle says, also necessary to know exactly what the alloy is because the process is matched to it, and there are many different High Speed Steels about.  Bottom line, we buy HSS in the hardened state and grind it to shape. It can’t be annealed, tempered, or rehardened.    Even normalising is difficult.

In contrast, Silver Steel and Gauge Plate are carefully formulated to simplify hardening and tempering using ordinary methods.  Supplied soft so it can be filed and machined.   Hardened simply by heating with a torch to about red-hot, and then plunging in oil or water.  Tempering can be done by chasing colours with the same torch, or soaking in a domestic oven.   Silver steel is ideal for making wood-working and metal cutting form tools.   Not as hard-wearing as HSS, but it’s good stuff.

I liked the video, but beware the internet! There is no quality control. What you get varies between excellent and awful.  Quite fun spotting mistakes.  In this one, it’s the phrase “HSS Drill Rod”.  Probably a typo or brain-fart: it’s just “Drill Rod”.

Dave

To fuel the discussion of ambiguity …

https://www.cromwell.co.uk/shop/cutting-tools/drill-blanks/c/391501

MichaelG.