Publishes a hardness — and calls the same steel carbide
KinRite Seven-holder 1/2 in set with C6 TiN inserts
The only listing on this shelf to publish a holder hardness — HRC 48 — in the same sentence that calls the holder cemented carbide.
This listing publishes two figures nobody else on this shelf does, and then contradicts one of them in the same sentence. The figures are a holder hardness of around HRC 48 and the holder lengths: two boring holders at 150 mm (5.91 in) and five at 100 mm (3.94 in), with a 95-degree lead angle and the hand of each boring bar given. The contradiction is the noun — the holders are described as “quality cemented carbide and tungsten steel（40CrMo）”, and 40CrMo at HRC 48 is a hardened alloy steel, not carbide.
The length data is genuinely useful. A boring bar can reach about three to four times its own diameter before chatter sets in, so the 50 mm (1.97 in) difference between the long and short holders is the difference between finishing a deep bore and giving up halfway. No other kit on this shelf tells you how long its holders are.
On the inserts, the specification is C6 grade with a TiN coating, a positive rake and a built-in chip breaker — the geometry this hub’s buying tip asks for on a light machine, stated plainly. They arrive fitted, with screws and a wrench. What is not here is a spare: seven holders, seven inserts, and the first chipped corner means an order. And as on four other pages here, “1/2”” and 12 mm (0.47 in) are used as if they were the same thing.
Availability
Read on the day this page was built: $40 at the American Amazon shop.
Read from Keepa on the day this page was last revised; stock and price both move without notice.
Prices quoted in this text were read on 2026-10-07. The live price is at the top of the page.
The questions welders ask
Carbide or steel?
Steel, and the listing’s own figures prove it. It describes the holders as "quality cemented carbide and tungsten steel（40CrMo）, HRC up and down 48 degrees". 40CrMo is a chromium-molybdenum alloy steel and HRC 48 is a hardened-steel hardness; cemented carbide is far harder and is measured on the HRA scale. A carbide tool holder would cost many times this and would shatter if dropped. What is being described, correctly in its figures and incorrectly in its noun, is a hardened alloy steel holder — which is what every holder on this shelf is.
What does C6 mean on an insert?
It is an American grade classification for carbide in steel cutting — roughly, the harder and more wear-resistant end for finishing rather than the tougher grades for roughing. Combined with a TiN coating and a positive rake, that is a finishing-oriented insert, which suits a light lathe taking small cuts. It is less information than an ISO designation would give, and more than five listings on this shelf provide.
Why does the 150 mm (5.91 in) boring holder length matter?
Because it sets how deep a bore you can reach. The two S12M-SCLCR06 and SCLCL06 holders are 150 mm (5.91 in) long against 100 mm (3.94 in) for the other five, and a boring bar can only reach about three to four times its own diameter before it starts to chatter — so the extra 50 mm (1.97 in) is the difference between boring a 40 mm (1.57 in) hole and stopping short. Publishing the lengths separately is a real courtesy; no other kit on this shelf does it.
