Drill Set

Quick Answer: The Drill Set is a set of twist drill bits in graded sizes for making round holes in metal, wood and plastic with a hand drill, power drill or drill press. A drill bit set covers the range of hole sizes needed for fixings, assembly and project work.

How a Twist Drill Cuts

A twist drill has two cutting lips at its point and two helical flutes that lift chips out of the hole. The point angle for general-purpose bits is commonly 118 degrees, which suits mild steel, aluminium, brass, wood and most plastics, and the straight shank is gripped in a three-jaw chuck. Bits for metal are commonly made of high-speed steel; the material, number of bits and size range of this set should be confirmed before ordering.

Speed must fall as diameter rises. A small bit can turn fast, but a large bit at the same speed moves its outer edge too quickly, overheats and loses its hardness, turning blue and blunt. Hard metals also need slower speeds than wood or plastic. On steel, a centre punch mark stops the point wandering, a small pilot hole makes large holes easier, and a few drops of cutting oil cool the edges.

The most important safety rule is to clamp the work. A drill that snags can spin an unclamped plate like a blade, so small parts should be held in a vice or clamped to the drill table. For hand-held jobs the work is gripped in a bench vice, and burrs left around the hole are removed afterwards with a countersink or a file.

Specifications

Care & Handling

• Clamp the work, wear eye protection, tie back hair and keep sleeves clear of the chuck.
• Remove the chuck key before starting the drill.
• Ease the pressure as the drill breaks through, where it tends to grab.
• Return bits to their marked places in the case so sizes stay sorted and edges protected.

Applications

• Drilling holes for bolts, rivets and screws in fitting and fabrication exercises
• Making mounting holes in wood and acrylic for STEM and robotics projects
• Drilling tapping holes before cutting internal threads
• Pilot holes for screws in hardwood to prevent splitting

Why Choose LabEquip

Fitting and fabrication trades, school technology rooms and STEM labs all need a graded set of twist drills rather than odd loose bits. LabEquip lists this set in the General Lab Products range; tell us the size range and quantity you require on the contact page.

Frequently Asked Questions

What speed should I drill at?

Use slower speeds for larger bits and harder materials, and faster speeds for small bits in wood and plastic. If the chips turn blue or the bit squeals, the speed is too high or the pressure too low. Drill press charts give starting values.

Why does the drill wander at the start?

The chisel edge at the centre of the point does not cut well and can skate on a smooth surface. Make a centre punch mark, or drill a small pilot hole first, so the point has somewhere to locate.

Do I need cutting fluid?

On steel, yes: a few drops of cutting oil cool the edges and help the chips flow, which extends bit life. Brass and cast iron are usually drilled dry, aluminium benefits from a lubricant, and wood and plastics need none.

Can these bits drill masonry or glass?

No. Twist drills for metal and wood are not made for masonry, concrete, tiles or glass, which need masonry or special glass bits. Using the wrong bit damages both the bit and the material.

How do I drill plastic without cracking it?

Use a sharp bit, moderate speed and light pressure, back the sheet with scrap wood, and ease off as the bit breaks through. Acrylic in particular cracks if the bit grabs at breakthrough.

How do I know if a bit is blunt?

A blunt bit needs more pressure, produces dust or powder instead of curls on metal, squeals, or leaves a ragged hole. Blunt bits can be resharpened on a grinder with a drill-sharpening jig, or replaced.

Last Updated: September 2026