The HSS (High Speed Steel) materials used in these HSS twist drill bits have many grades. In China, the common HSS grades to make twist drill bits are 4241, 4341, 9341, 6542, M35. Except M35, the numbers in these grade names represent the approximate percentages of tungsten, molybdenum, chromium and vanadium in the HSS material. That is, 4241 — W4Mo2Cr4VSi, 4341 — W4Mo3Cr4VSi, 9341 — W9Mo3Cr4V, 6542 — W6Mo5Cr4V2. 6542 is just the M2 in the AISI standard, and M35 (also a name in AISI, W6Mo5Cr4V2Co5) has additional 5% cobalt comparing with M2.
The 4241 materials are used to make economical twist drill bits, which are in our “Below Medium” quality grade. The 4341 twist drill bits are of common performance and are in our “Medium” grade. The performance of 9341 and 6542 (M2) is good, and the drill bits made with them are in our “Above Medium” grade. The comprehensive performance of 9341 is a little bit better than 6542 and 9341 is cheaper. The M35 HSS drill bits are in our “High” grade. They can be used to drill stainless steel, for M35 HSS material contains additional 5% cobalt, which can increase the HSS material’s capability to keep its high hardness under the high temperature generated in the drilling.
The 9341, 6542 and M35 HSS drill bits can be solid ground (fully ground). The solid-ground drill bits are much better than the rolled ones, and their prices are also much higher. The 9341 and 6542 solid-ground drill bits are in our “High” quality grade.
The 4241 and 4341 HSS drill bits can be coated with nitride or titanium, which can improve the drill bits’ durability and cutting efficiency.
|HSS Twist Drill Bit Nitride Coated Straight Shank||HSS Twist Drill Bit Straight Shank|
|HSS Twist Drill Bit Titanium Coated Straight Shank|