5-3. RIVET REPLACEMENT (CONT).
The rivet code designation gives the type of rivet, the material, the diameter in 32nds of an inch, and the
length in 16ths of an inch.
The determination of the length of a rivet is an important part of any repair. The length used depends on
the grip or combined thickness of material to be riveted plus a minimum allowance of 1/2 diameter for upsetting the
Always use the nearest standard rivet length greater than the calculated sum.
(3) There are specific considerations in laying out the rivet pattern for a repair; these rules apply generally in all
When possible, rivet edge distance, rivet spacing, and distance between rows should be the same as
that of the original installation.
When new sections are added, the edge distance measured from the center of the rivet should never be
less than two times the diameter of the shank. The distance between rivets or pitch should be at least three times the
diameter; the distance between rows should never be less than 1/2 times the diameter.
Mark the rivet pattern on the metal with a soft pencil to avoid scratching.
(4) Rivet holes may be drilled with either a light power drill or a hand drill (standard shank twist drill).
Before drilling, center-punch all rivet locations. The center-punch mark should be large enough to
prevent the drill from slipping out of position.
Place drill in center-punch mark. When using a power drill, rotate the bit a few turns by hand before
starting motor. While drilling, always hold drill at a 90-degree angle to work.
Avoid excessive pressure; let the drill do the cutting. Never push drill through stock. Remove all burrs
with a metal countersink or file.
Transfer holes from drilled part to another part by placing second part over first and using established
holes as a guide.
After drilling and before you drive rivets, the metal sheets must be held securely in position to prevent
slippage during riveting. When two pieces of metal have been drilled through, use any of several types of available skin
fasteners to hold them in alignment.
5-4. WELDING. MFK components such as the storage rack assembly, oven assembly, burner and base racks, steam
table assembly, heater tank assembly, cooking pot cradle assembly and work tables may require welding. Refer to TM 9-
237 for information on welding theory and application.