Name	3PCS HSS nitriding sprial flute step drill bit set
Material	HSS 4241, HSS 4341, HSS M2(6542) and M35 for choose. This is M35 material.
Flute	double spiral flute.
Tip degree	135 degree with split point
Surface treatment	black oxidation finish
Size	Metric size from 4 to 30mm by increment 2mm; from 4 to 20mm by increment 2mm; from 4 to 12mm by increment 2mm;
Mark	mark size on flute by lasering. And mark LOGO or brand on shank.
Shank	round/ straight shank with Tri-flats.
Package	3PCS HSS nitriding sprial flute step drill bit set, 3PCS packed in a grey plastic rose box; we also have other box and package for you choose;
Brand	GMTOOL, We also accept custom customers' brand (OEM).

● Premium M35 HSS - Constructed from M35 high speed steel with 5% cobalt content, these step drill bits offer exceptional durability and superior cutting performance, even on tough materials like stainless steel (＜1mm).
● Advanced Tialn Coating - The 3PCS HSS nitriding sprial flute step drill bit set Titanium Aluminium Nitride (TiAlN) coating ensures high hardness and excellent wear resistance, extending the lifespan of the drill bits and maintaining sharpness for longer periods.
● 118°X Type Openings Design - Designed with a spiral flute for smooth, clean drilling and enhanced chip removal. Achieve precise holes effortlessly, reducing the need for multiple drill bits.
● Tri-flats Shank: round shank with 3-falts, which can be easily fit into power driver, drill and press drill, and provide effective grip strength. eliminate slipping in drill chuck, these step drill bit for metal are compatible with a range of drilling tools including bench drills press, impact drills, and hand drills, making them a versatile addition to your toolkit.
● Ideal For Diy & Professional Use - Whether you're a DIY enthusiast or a professional, this step drill bit set is perfect for various applications, including drilling in sheet metal, aluminium, copper, plastic, and more. Not only can it enlarge holes, but it also deburrs, chamfers, and cutting.

Usage: take out the drill bit which you want size by carefully and install it in drill machine, clamp it tightly by key, then adjust the speed around 550 RPM, Apply pressure uniformly downward.

Kind Tips - To prevent overheating and potential damage to the drill bits, always use cutting oil or spraying water during operation. Proper cooling extends the life and efficiency of the bits.