Master Lock 140

Difficulty Notes

The definitive yellow belt lock. A gentle introduction to spool pins and false sets. Most pickers find this to be the first lock that teaches them what a false set actually feels like.

Picking Notes

SPP is the way to go. Set the standard pins first, then work through the spools. When you hit a false set, lighten tension slightly and push through. The keyway is wide open — no warding issues. Raking can also work but you won't learn as much.

Tension Tips

Bottom of keyway (BOK) tension with light-to-medium pressure. TOK works too but BOK is easier to start with on this lock. Light tension is key for navigating the spools — too heavy and you'll overset.

False Set Behavior

Expect one solid false set when the spool pins engage. The core will rotate maybe 15-20 degrees and stop. That's your signal to lighten up and carefully push the remaining pins. Very satisfying when it clicks open from a false set.

Bitting Variance

Production varies — some 140s have 2 spools, some have 3 out of 4 driver pins as spools. The 140 and 141 are the same lock, just different packaging. Older production runs may have fewer security pins. Gut yours to know what you're working with.

Gutting Notes

Easy to gut with a follower. Brass body comes apart cleanly. Springs are standard weight. Pin chambers have reasonable tolerances — not as sloppy as a Master #3 but not precision either.

Recommended Tools

• Peterson Hook 1 in 0.025
• Peterson Pry Bar (BOK tension)
• Any standard short hook in 0.025 will work
• TOK tension wrench if you prefer top-of-keyway

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