Ever since we used these Ultra Smooth Tri-Cut Auger Bits by Star-M, we have wanted to stock them. Izzy first used one of these triple fluted auger bits on a course with Woodsmith's friend Mountain Oak Woodcraft on their timber framing course in the South Lakes. Ever since then, and as we've been developing our timber framing offering at Woodsmith, we have had many requests from professional timber framing customers and beyond to stock these powerful and smooth auger bits from Star-M (branded as WoodOwl in the US), so we're delighted to be finally able to offer them to you.

Precision made in Japan, these triple fluted auger bits are made from high carbon steel with a fluorine coating, making them incredibly smooth and also rust resistant, non-stick, low-friction, and heat resistant. Less effort for you and your drill battery!

The three precision-ground cutting edges make starting and boring into timber efficient and smooth. The lead screw also helps the spurs to scribe and pulls the bit in confidently for clean, precise holes with minimal tear out/ blow out at the back of the mortice. They work in both power drills and hand braces.

These auger bits are seen as stalwart figures amongst the professional timber framing community, but are also popular with chairmakers and carpenters, or anyone who has need for clean, precise holes or mortices.

Please note - whilst the durability, power, and efficiency of the Ultra Smooth Tri-Cut Auger Bits are greatly superior to others we've tested, if you are looking for either cheaper options or alternatives which are easier to sharpen, we recommend taking a look at the alternative drill bits available by Star-M such as the Combination Auger Bit No.6, the Power Auger Bit No.4 or the Extra Long Power Auger Bit. That said, you will hopefully find that the Ultra Smooth Tri-Cut Auger Bits make up for their ease of resharpening with durability and longevity!

Short Type

• Total length: 190mm, approx 7 1/2"
• Shank length: 55mm
• Flute length: 135mm
• Shank diameter: 12.55mm hex
• Available flute diameters: 
  • 13mm (approx. equivalent in inches: 1/2")
  • 19mm (approx. equivalent in inches: 3/4")
  • 25mm (approx. equivalent in inches: 1")

Long Type:

• Total length: 457mm, approx 18"
• Shank length: 76mm
• Flute length: 381mm
• Shank diameter: 12.55mm hex
• Available flute diameters: 
  • 13mm (approx. equivalent in inches: 1/2")
  • 19mm (approx. equivalent in inches: 3/4")
  • 25mm (approx. equivalent in inches: 1")
  • 32mm (approx. equivalent in inches: 1 1/4")

All Star-M Ultra Smooth Tri-Cut Auger Bits come in a solid plastic reusable casing for transportation and protection when not in use.

About Star-M:

Star-M is a Japanese tool manufacturer with a legacy of producing high-quality drilling and woodworking accessories since 1923. Known for their precision engineering and thoughtful design, Star-M’s products are developed in Japan and manufactured to exacting standards at their facility in Miki City - a region with a rich history of blacksmithing and edge tool production.

Star-M's range includes innovative woodworking drills, screw tip augers, tenon cutters, countersinks, and specialist bits ideal for green woodworking, joinery, and fine carpentry. Each product reflects the company’s commitment to usability, durability, and clean cutting performance – whether you're using a cordless drill on-site or a hand brace in the workshop.

At Woodsmith, we’re proud to stock a curated selection of Star-M products trusted by green woodworkers, chairmakers, and timber framers across the UK and beyond.