M2x4 Rivet Uses on Mini Lathe and Mill Assemblies

By Products for bench top machinists | LittleMachineShop.com | Published: 2026-11-01

Category: How-to Guides

Learn where the M2x4 rivet fits on mini lathe and mill assemblies, how to replace a missing scale rivet, and the checks that prevent a loose or damaged fit.

Quick answer

Use the M2x4 rivet as a small retainer for scales and similar light-duty parts on mini lathe and mill assemblies. Replace a missing or loose rivet with the same M2 x 4 size, seat it fully without crushing the scale, and confirm the part still moves or reads freely.

Why a small rivet matters more than its size suggests

On a bench lathe or mill, the M2x4 rivet is not a structural fastener. It holds a thin scale or similar light part in place, so a missing rivet can let the scale shift and give you a false reading. The small size also means the rivet is easy to lose and easy to overdrive if you treat it like a larger fastener.

When to replace rather than reuse

Replace the rivet when the head is worn, the shank is bent, or the rivet no longer holds the scale flat. Reusing a deformed rivet can enlarge the hole in a thin scale, and that damage is harder to fix than swapping the rivet.

Step-by-step rivet replacement

Confirm the rivet size and location: Measure the old rivet or check the parts diagram for your machine. The M2x4 rivet is 2 mm in diameter and 4 mm long, and on the SC4 it is part # 14. Compare the hole diameter and scale thickness before ordering. If the old rivet is missing, use the parts diagram rather than guessing from the hole size alone.
Support the scale before removal: Place a thin, flat support behind the scale so the rivet can be pressed or tapped out without bending the scale. Work over a tray to catch the rivet. A scale that flexes during removal can crack or lose its flatness.
Clean the rivet hole: Remove burrs and debris from the hole in the scale and the mating part. Check that the new rivet passes through without force. A tight hole can make the rivet bend instead of seating.
Seat the new rivet: Insert the M2x4 rivet and press or tap it only until the scale is held snug. Stop as soon as the scale stops moving; do not crush the rivet head into the scale. Overdriving a small rivet distorts the scale and can enlarge the hole.
Check the assembly: Move the scale or the part it reads against through its full range. The scale should stay flat and secure, and the rivet should not rub or bind. If the scale binds, stop and check that the rivet is fully seated before using the machine.

Product facts

Rivet, M2x4: M2 x 4 tailstock rivet listed as part # 14 on the SC4 parts diagram (SC4-14). This identifies the exact position on the SC4 diagram, so you can confirm the rivet matches the scale-retention location before ordering.
Rivet, M2x4