carbon or HSS

For the interest of the members I have just done a spark test on a HQS tap from Tap and Die, a typical display as produced by high carbon steel and very different from the HSS tap I used as a control. I am confident that HQS is a high carbon steel, I am also quite happy that it is a good tap that is fit for purpose although I may choose something else if I was buying for a high volume production use.

Mike

.

Thanks, Bill … that is probably as good as we will get

Obfuscation was a word that sprang to mind,

… but I will settle for ‘we need to read between the lines’

interesting to note, for example, that it “cuts into even virgin stainless steel”

[none of your work-hardened mucked-about-with stuff]

MichaelG.

Am I to understand that the Tap and Die Company don't actually sell HSS taps, and that all of their taps are made of "HQS"?

If that is the case, I hope I'm not being overly cynical in tentatively concluding that they're selling what are essentially carbon steel taps (good ones, maybe) whilst trying to claim they're in a special qualitative category that puts them (implausibly, in my view) above more expensive HSS taps.

I've not actually checked that their HQS taps are cheaper than typical HSS taps, but I assume from Peak4's quoted blurb on the first page of this thread that they are.

Edited By Bill Phinn on 12/09/2022 17:56:08

I expect there are both high and low quality taps and dies in both high carbon and HSS versions. So it not a simple clear-cut choice between the two materials.

‘Cheap’ is more likely to be low quality, in my experience. It may not be the wear or breakage resistance - but also the finished thread-form achieved.

I have mostly HSS examples - all I have bought new, in recent years, have been HSS - but I do have some older high carbon examples which I only use for thread chasing/repair these days.

No they sell both

Thanks, Keith. I've had a look at the "ordering site" now, and I see that's the case.

However, the logic of the seller's claims about "HQS" and HSS escapes me.

His offerings of the latter are described as "superior", which may be intended to mean superior in an absolute rather than a comparative sense, even if his HSS taps are routinely more expensive than his "HQS" equivalents.

But then he completely spoils the eulogy of his HSS stuff by describing his cheaper "HQS" offerings as "a tougher and better alternative to HSS". If what we want to buy is something "superior" in a comparative sense, which of the two does he actually want, or advise, us to buy?

In his eagerness to sing the praises of both HSS and "HQS", the seller appears to have lost track of the message he is ultimately conveying about each.

I think we generally agree that HSS is tougher than CS and we tend to favour the former where resistance to breakage is important. However, the main advantage of HSS is retention of hardness at high temperature. If you don't need this property (and which of us does?) then possibly HQS is equally tough without the expense of retaining hot hardness.

Rod

There are two problems there, Rod:

First, the seller has said "HQS" is considered "tougher than HSS"; second, what assurance do we have that "HQS", whatever it is compositionally, is actually as tough as or tougher than HSS?