Proxxon HSS twist drill bit set, 10 pieces in case, 0.3–3.2 mm

Proxxon HSS twist drill bit set – 10 bits from 0.3 to 3.2 mm in a case

The Proxxon HSS twist drill bit set (art. no. 28874) contains 10 twist drill bits from 0.3 to 3.2 mm for drilling non-ferrous metal, steel and stainless steel. The bits are made of HSS (High Speed Steel) and are similar to DIN 338. They come in a labelled case with a fold-open and stand function: you can see each diameter at once and have the bits within easy reach as you work.

The set covers the fine holes found in model making, precision engineering and jewellery or craft work in metal. Each diameter is included once.

Which diameter for which job?

The graduated sizes from 0.3 to 3.2 mm help you match the hole exactly to a wire, pin, rivet or screw. For a through hole, choose a bit slightly larger than the part that needs to pass through. If a thread is to be cut, pre-drill with the tap drill diameter given in the tap's table. The very thin bits under 1 mm break easily and are suited to fine holes in thin material.

Drilling cleanly in metal

Clamp the workpiece firmly, as a slipping workpiece is the most common cause of broken thin bits. Centre-punch the spot so the bit does not wander. Drill without side pressure and with a steady, light feed. Small diameters run at a higher speed, larger ones at a lower speed. For deeper holes, lift the bit now and then so the swarf is cleared. In steel and stainless steel, cutting oil extends the life of the bit. Wear safety goggles when drilling.

Proxxon HSS twist drill bit set 28874 product details

• Manufacturer: Proxxon, art. no. 28874
• Contents: 10 twist drill bits, 1 of each diameter
• Diameters: 0.3 / 0.5 / 0.8 / 1.0 / 1.2 / 1.5 / 2.0 / 2.5 / 3.0 / 3.2 mm
• Material: HSS (High Speed Steel)
• Standard: similar to DIN 338
• Suitable for: non-ferrous metal, steel, stainless steel
• Storage: labelled case with fold-open and stand function

You will also need: A drill or drill stand with a chuck that grips very thin bits securely, plus a centre punch and hammer for marking the holes. Cutting oil is useful for steel and stainless steel.