Drilling and tapping machine

Industrial DM 7/8UNF Ø20.5LF Thermal Friction Drill Bit Wholesale

DM 7/8UNF Ø20.5LF / Grade T

Model: DM 7/8UNF Ø20.5LF / Grade T

Function: CNC Drilling, Thermal friction drilling, Flow drill

Application Materials: Iron, Zinc, Steel, Stainless Steel, Tool Steel, Inconel, Hastelloy, Aluminum, Carbide, Titanium, Tungsten, Tantalum, Copper, Brass, Bronze, Platinum etc.



Feature

Professional-grade bit for high-speed friction drilling of metal tubes and plates. Consistent quality for OEM users.

Lead time (days) : 7 to 10 working days. (Standard Configuration)

Tip: Our CNC drilling and tapping machines support custom non-standard designs, machine color customization, and OEM branding. Start now to purchase and customize your own equipment, please contact us.

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Technical specification

Technical specification

  • Thread Size
    7/8UNF
  • Diameter
    Ø20.5 mm
  • Finishing
    Plane Surface
  • Materials
    Tungsten Carbide
  • Brand
    DUOMI ( DM )

Introduction

  • DM thermal drill bits use frictional heat to form tough, elongated bushings. The standard model retains the extruded ring; the flat version removes it for smooth surfaces. They require no chip cleaning and deliver excellent tapping strength. Applied in automotive frames, stainless furniture, aerospace panels, lighting systems, plating lines, and temperature-control tubes.


    DM 7-8UNF Ø20.5mm Long Flat Flow Drill Bits.jpg

Key benefits

  • Guide to Choosing Thermal Friction Drill Bits

    Thermal friction drill bits come in two main types: standard round-mouth and flat-mouth (planed) designs.

    Standard Type: Forms an extrusion sleeve while also creating a raised collar on the surface.

    Flat Type: Produces the same extrusion sleeve but simultaneously removes the surface collar, keeping the surface smooth.


    Advantages of DM Thermal Drill Bits

    Chipless forming with high tensile and torsional thread strength.

    Zero chip generation—no need for waste removal.

    High accuracy when forming collars and bushings.

    Compatible with most tapping machines.

    High speed, long service life, and increased productivity.

    Suitable for a wide variety of materials that support thermal drilling.


    Typical Applications

    Extended thread requirement

    Welded structures and multi-layer heat exchangers

    Bearing housings

    Stainless steel architectural components and metal furniture joints


    Industries Served

    Automotive manufacturing

    Bicycle production

    Stainless steel furniture fabrication

    Aerospace

    Central heating systems

    Lighting equipment manufacturing

    Machinery and metal construction

    Electroplating and coating industries

    Liquid-cooling tubes


Customer Testimonials

  • Martin Keller

    Martin Keller

    ★★★★★

    Germany

    " We switched to DM flow-drill bits last year and never looked back. The tool life is outstanding and the holes are perfectly extruded every time. The best thermal drill bits for industrial shops. "

    Jacob Thompson

    Jacob Thompson

    ★★★★★

    USA

    " Great performance! These thermal drilling tools form strong bushings without cracking the material. DM flow-drill bits outperform everything we used before. "

    Sofia Ramirez

    Sofia Ramirez

    ★★★★★

    Mexico

    " DM thermal drill bits give us clean, accurate holes on aluminum frames. No chips, no mess, and incredibly stable temperature control. Perfect tools for high-volume production. "

    Oliver Bennett

    Oliver Bennett

    ★★★★★

    United Kingdom

    " The consistency of these flow-drill bits is unmatched. Perfect extrusion height and excellent wear resistance. DM thermal drilling tools are worth the investment. "

    Derek Wilson

    Derek Wilson

    ★★★★★

    Canada

    " These thermal drilling tools produce strong sleeve-like holes without secondary processing. DM flow-drill bits reduced our cycle time by 40%. Excellent quality. "

    Arjun Patel

    Arjun Patel

    ★★★★★

    India

    " We use DM thermal drill bits for large batch orders. Zero failure rate and very long lifespan. These thermal drilling tools have become our factory standard. "

    Chris Evans

    Chris Evans

    ★★★★★

    Italy

    "Durable, efficient, and precise—this CNC drilling machine has been a valuable addition to our workshop!"

    Ahmad Yusuf

    Ahmad Yusuf

    ★★★★★

    Indonesia

    " DM flow-drill bits are extremely reliable. The hole forming on steel frames is always clean and precise. Perfect for automotive parts manufacturing. "

    Emilia Novak

    Emilia Novak

    ★★★★★

    Poland

    " High stability, no burrs, and very strong threaded sleeves. These thermal drill bits perform better than the German brands we used before. Very impressive tools. "

    Samuel Okoro

    Samuel Okoro

    ★★★★★

    Nigeria

    " Our metal fabrication team loves DM thermal drilling tools. Smooth forming and long service life. These flow-drill bits help us achieve excellent accuracy. "

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