TiAlN Coated Industrial Grade HSS 8% Cobalt Twist Drill Bit

Product Overview

Our M42 HSS 8% cobalt twist drill bits are purpose-engineered for heavy-duty, high-difficulty industrial drilling operations, delivering exceptional performance in hard-to-machine materials that standard HSS drill bits cannot handle reliably.

Manufactured with 8% cobalt-alloyed M42 high-speed steel and premium TiN gold coating, these drill bits are the trusted choice for B2B partners including stainless steel fabricators, automotive component manufacturers, aerospace machining facilities, mold & die workshops, hardware distributors, and global MRO service providers. We deliver unrivaled batch consistency, extended tool life, and reduced total operational cost for high-volume production and continuous drilling applications.

● Titanium Aluminum Nitride Coating (TiAlN) increases surface hardness to 89HRC with outstanding heat-resistance, so our drill bit cuts fast and stay sharp.

Ideal Industrial Applications

Our 8% cobalt twist drill bits are the industry standard for:

Stainless steel fabrication & kitchenware manufacturing
Automotive & heavy truck component machining
Aerospace & defense parts production
Mold & die manufacturing
Medical device & precision instrument machining
Oil & gas equipment repair & production
Industrial MRO & maintenance operations
Metalworking job shops & contract manufacturing

B2B Bulk Supply & Customization Solutions

As a professional industrial cutting tool manufacturer with over 20 years of experience serving global B2B clients, we offer flexible, reliable supply solutions tailored to your business needs:

Bulk Wholesale Support: Large-scale production capacity for high-volume orders, with competitive factory-direct pricing to maximize your profit margin
OEM & ODM Customization: Full support for custom sizes, coatings, packaging, private labeling, and logo printing to match your brand and application requirements
Stable Inventory & Fast Delivery: Full stock of standard sizes for immediate global shipment, with guaranteed lead times for custom orders
Flexible MOQ: Trial orders available for new partners, with scalable minimum order quantities for long-term cooperative clients
Full Compliance Support: We provide all necessary certification documents, including ISO 9001, RoHS, and REACH, to support your cross-border procurement and market access

Application
HSS Grade	Iron	Aluminum	Carbon Steel	Tile	Plastic	Stainless Steel
4241	YES	YES	NO	NO	YES	NO
4341	YES	YES	YES	NO	YES	YES
6542(M2)	YES	YES	YES	NO	YES	GOOD
M35 (Co 5%)	YES	YES	YES	NO	YES	VERY GOOD

DESCRIPTION OF HSS	C	W	Mo	Cr	V	Co	Si	Mn	P	S
	%	%	%	%	%	%	%	%	%	%
W4Mo3Cr4V(4341)	0.88-0.98	3.5-4.5	2.5-3.5	3.8-4.4	1.2-1.8		0.5-1.2	0.2-0.4	<=0.03	<=0.03
W6Mo5Cr4V2(M2)	0.8-0.9	5.5-6.75	4.5-5.5	3.8-4.4	1.75-2.2	–	0.2-0.4	0.2-0.4	<=0.03	<=0.03
W6Mo5Cr4V2Co5(M35)	0.9-0.95	5.5-6.5	4.5-5.5	3.8-4.4	1.75-2.2	4.5-5.5	0.2-0.4	0.2-0.4	<=0.03	<=0.03
W2Mo9Cr4V2Co8(M42)	1.05-1.15	1.15-1.85	9.0-10.0	3.5-4.25	0.95-1.25	7.75-8.75	0.15-0.65	0.15-0.4	<=0.02	<=0.025

Metric size

DIA.(mm)	OVERALL LENGTH(mm)	WORKING LENGTH(mm)
1	34	12
1.5	43	20
2	49	24
2.5	57	30
3	61	33
3.5	70	39
4	75	43
4.5	80	47
5	86	52
5.5	93	57
6	93	57
6.5	101	63
7	109	69
7.5	109	69
8	117	75
8.5	117	75
9	125	81
9.5	125	81
10	133	87
10.5	133	87
11	142	94
11.5	142	94
12	151	101
12.5	151	101
13	151	101
13.5	160	108
14	160	108
14.5	169	114
15	169	114
15.5	178	120
16	178	120
16.5	184	125
17	184	125
17.5	191	130
18	191	130
18.5	198	135
19	198	135
19.5	205	140
20	205	140

Imperial size

DIA.	OVERALL LENGTH (INCH)	WORKING LENGTH (INCH)	DIA.	OVERALL	WORKING LENGTH (INCH)	DIA.	OVERALL	WORKING LENGTH (INCH)
1/64″	3/4″	3/16″	15#	3-3/8″	2-3/16″	61#	1-/5/8″	11/16″
1/32″	1-3/8″	1/2″	16#	3-3/8″	2-3/16″	62#	1-1/2″	5/8″
3/64″	1-3/4″	3/4″	17#	3-3/8″	2-3/16″	63#	1-1/2″	5/8″
1/16″	1-7/8″	7/8″	18#	3-1/4″	2-1/8″	64#	1-1/2″	5/8″
5/64″	2″	1″	19#	3-1/4″	2-1/8″	65#	1-1/2″	5/8″
3/32″	2-1/4″	1-1/4″	20#	3-1/4″	2-1/8″	66#	1-3/8″	1/2″
7/64″	2-5/8″	1-1/2″	21#	3-1/4″	2-1/8″	67#	1-3/8″	1/2″
1/8″	2-3/4″	1-5/8″	22#	3-1/8″	2″	68#	1-3/8″	1/2″
9/64″	2-7/8″	1-3/4″	23#	3-1/8″	2”	69#	1-3/8″	1/2″
5/32″	3-1/8″	2″	24#	3-1/8″	2″	70#	1-1/4″	3/8″
11/64″	3-1/4″	2-1/8″	25#	3″	1-7/8”	71#	1-1/4″	3/8″
3/16″	3-1/2″	2-5/16″	26#	3″	1-7/8″	72#	1-1/8″	5/16″
13/64″	3-5/8″	2-7/16″	27#	3”	1-7/8″	73#	1-1/8″	5/16″
7/32″	3-3/4″	2-1/2″	28#	2-7/8″	1-3/4″	74#	1″	1/4″
15/64″	3-7/8″	2-5/8″	29#	2-7/8″	1-3/4″	75#	1″	1/4″
1/4″	4″	2-3/4″	30#	2-3/4″	1-5/8″	76#	7/8″	3/16″
17/64″	4-1/8″	2-7/8″	31#	2-3/4″	1-5/8″	77#	7/8″	3/16″
9/32″	4-1/4″	2-15/16″	32#	2-3/4″	1-5/8″	78#	7/8″	3/16″
19/64″	4-3/8″	3-1/16″	33#	2-5/8″	1-1/2″	79#	3/4″	1/8″
5/16″	4-1/2″	3-3/16″	34#	2-5/8″	1-1/2″	80#	3/4″	1/8″
21/64″	4-5/8″	3-5/16″	35#	2-5/8″	1-1/2″	A	3-/7/8″	2-5/8″
11/32″	4-3/4″	3-7/16″	36#	2-1/2″	1-7/16″	B	4″	2-3/4″
23/64″	4-7/8″	3-1/2″	37#	2-1/2″	1-7/16″	C	4″	2-3/4″
3/8″	5″	3-5/8″	38#	2-1/2″	1-7/16″	D	4″	2-3/4″
25/64″	5-1/8″	3-3/4″	39#	2-3/8″	1-3/8”	E	4″	2-3/4″
13/32″	5-1/4″	3-7/8″	40#	2-3/8″	1-3/8″	F	4-/1/8″	2-7/8″
27/64″	5-3/8″	3-15/16″	41#	2-3/8″	1-3/8″	G	4-/1/8″	2-7/8″
7/16″	5-1/2″	4-1/16″	42#	2-1/4″	1-1/4″	H	4-/1/8″	2-7/8″
29/64″	5-5/8″	4-3/16″	43#	2-1/4″	1-1/4″	I	4-1/8”	2-7/8″
15/32″	5-3/4″	4-5/16″	44#	2-1/8″	1-1/8″	J	4-/1/8″	2-7/8″
31/64″	5-7/8″	4-3/8″	45#	2-1/8″	1-1/8″	K	4-/1/4″	2-15/16″
1/2″	6″	4-1/2″	46#	2-1/8″	1-1/8″	L	4-/1/4″	2-15/16″
1#	3-7/8″	2-5/8″	47#	2″	1″	M	4-3/8″	3-1/16″
2#	3-7/8″	2-5/8″	48#	2″	1″	N	4-3/8″	3-1/16″
3#	3-3/4″	2-1/2″	49#	2″	1″	O	4-1/2″	3-3/16″
4#	3-3/4″	2-1/2″	50#	2″	1″	P	4-5/8″	3-5/16″
5#	3-3/4″	2-1/2″	51#	2″	1″	Q	4-3/4″	3-7/16″
6#	3-3/4″	2-1/2″	52#	1-7/8″	7/8″	R	4-3/4″	3-7/16″
7#	3-5/8″	2-7/16″	53#	1-7/8″	7/8″	S	4-7/8″	3-1/2″
8#	3-5/8″	2-7/16″	54#	1-7/8″	7/8″	T	4-7/8″	3-1/2″
9#	3-5/8″	2-7/16″	55#	1-7/8″	7/8″	U	5″	3-5/8″
10#	3-5/8″	2-7/16″	56#	1-3/4″	3/4″	V	5″	3-5/8″
11#	3-1/2″	2-5/16″	57#	1-3/4″	3/4″	W	5-1/8″	3-3/4″
12#	3-1/2″	2-5/16″	58#	1-5/8″	11/16″	X	5-1/8″	3-3/4″
13#	3-1/2″	2-5/16″	59#	1-5/8″	11/16″	Y	5-1/4″	3-7/8″
14#	3-3/8″	2-3/16″	60#	1-5/8″	11/16″	Z	5-1/4″	3-7/8″