Disassembling A 1959 Acme 74C

Any model of Langdon, Acme or All Steel from the 1950’s onward will come apart as described on this page with little variation, if any.

Some of the Goodell-Pratt “All Steel” miter boxes from the 1920’s and 1930’s are very similar in construction as well. The Goodell-Pratt hardware design seems to have been adopted by Millers Falls upon acquiring that company.

Before beginning you will want to study and perhaps print out the parts diagram.

Taking one of these boxes apart is not difficult but there are a few bits are not intuitive. As long as you exercise reasonable care and gentle persuasion even a rust-encrusted miter box may be easily disassembled.

Tools required for disassembly: 3/4″, 9/16″, 3/8″ combination wrenches; pliers; flat screwdriver.

Remove the saw guide posts and turn the unit upside down.

Remove the spring lever. It is held in with one screw and the notch that fits into the detent pin. Beware! The spring and spacer will want to run away on you as you unscrew this.

Spring lever. The little tab fits into the end of the spring and helps to hold it in place. Remember this when you reassemble the box!

King bolt with cup washer and nut removed. This holds the arm onto the base of the miter box. Careful, this is where things really start coming apart!

Locking lever on right, detent pin in center. The pin slips straight up and out. Unscrew the larger steel nut from the swing arm. The large steel nut holds the brass one in place. You’ll need a 3/4″ wrench for this.

Steel locknut with brass nut contained within it. If you find punched tick marks (barely visible here) then these are for alignment.

Observe the eccentrically drilled hole in the brass nut. The detent pin fits in that hole. Turning the nut adjusts the fit of the pin in the detents, permitting fine adjustment of the saw cut.

Locking lever is press fit onto the stud. You will have to rock it up and down to get it off as it is a press fit onto the toothed stud. Do NOT strip the stud’s teeth by turning the lever! Make sure you pull this lever vertically upward.

Unscrew the locking lever stud with a pair of pliers, avoiding the threads and toothing on the end of the stud itself. The other end of this stud screws into the underside of the gib.

Stud removed.

Gib removed.

Swing arm removed. Observe the grease puddle. Clean this out and regrease with any non-drippy bearing grease or white lithium (which is what I used here). This is the ONLY part on the entire box that ever gets lubricated.

Swing arm removed and disassembled.

The legs and bed plates are screwed in place from underneath.

Of course reassembly is primarily a matter of retracing one’s steps backwards. However, merely putting it all back together does not necessarily result in a miter box that will cut accurately. You shall have to fettle this tool before you start using it.