Simonds SIM73402500 Round Bastard File 12" American

The Simonds SIM73402500 is a round bastard file, American pattern, 12 inches.

The round bastard is the file that opens a hole, and it is the coarse end of a sequence rather than a finishing tool.

Its job is removal. A hole that is undersize, drifted, or the wrong shape needs metal taken out of it, and a bastard-grade round file takes it out fast. What it leaves is rough and slightly faceted, and that is expected — the second cut and smooth files in this range exist to fix it.

The technique is the thing that separates a round hole from a polygon. A round file must be rotated as it is pushed, roughly a quarter turn per stroke. Pushed straight, it cuts a flat on the bore wall, and repeated strokes in the same orientation cut that flat deeper. The result is a hole with faces on it. This is the single most common mistake with round files and it is invisible until something round has to go in.

At 12 inches the file tapers along its length, which means the effective diameter varies — one file covers a working range of hole sizes.

Bastard is the coarse grade in the American pattern system.

Fit a handle. The tang is a bare spike.

Brand

Simonds

SKU

SIM73402500

Category

Hand Tools

Weight

0.58 lbs

Dimensions

10.00 x 1.00 x 0.25

Price

$21.95

Availability

In stock

Rating

4 / 5.0