Master Lock Padlock Parts and Keys: What to Know Before Ordering

Master Lock padlocks are ordered by a model number plus letter codes, and only some models take replacement parts. This page explains how to read the number, which parts Master Lock lists for which padlocks, and what to have ready when you order keys or keyed alike padlocks.

Sources: Master Lock's Commercial Security Product Catalog (2021), its Commercial Price List effective August 2, 2022, and the Technical Manual (issue 06.13).

How to read a Master Lock padlock number

The price list builds a padlock number from a base model and option codes: its example 1 KA LJ CN NOKEY is a No. 1 padlock, keyed alike, with the LJ shackle, a chain and no keys. The keying codes, as Master Lock defines them:

Shackle codes such as LF, LJ and LN select a shackle option, and its clearance can depend on the model. For the No. 1 padlock, the catalog lists LF = 1-1/2in, LJ = 2-1/2in and LN = 5-3/4in; for the 7030, LF is 1-9/16in.

A key number can follow: to order a specific key number, the price list says to give the product number followed by the key number (No. 5KA A101 = No. 5 padlocks keyed alike to key A101); without one, Master Lock selects a random key number from the range for that model. A number such as 1KALF2944 reads the same way: No. 1, keyed alike, LF shackle, and 2944, inside the 2001-2997 key range the price list gives for No. 1 padlocks.

Shackle sizes: compare dimensions, not letters

The catalog drawings label shackle dimensions: A is the shackle diameter, B is the vertical clearance (from the lock body to the inside of the shackle), and C is the space between the shackle legs. Two things to watch:

• The same letter is not the same clearance on every model (see LF above).
• The catalog names the LJ option of the 6121 as 2-1/2in, but the price list gives it a B of 2-3/8in, the same as for the replacement shackle 293LJS6121.

Which Master Lock padlocks take replacement parts

• Pro Series padlocks such as 6121, 6127, 6321, 6840 and 7040: the catalog describes them as rekeyable, with a replaceable cylinder and shackle. All replacement shackles in the price list (293 numbers) are for Pro Series padlocks.
• Laminated padlocks Nos. 21, 24, 25, 27 and 101: according to the Technical Manual, they have a trap door you can remove so that the cylinder may be exchanged or rekeyed.
• Nos. 1, 2, 3, 4, 5 and 7: the catalog lists them under General Security Non-Rekeyables. For laminated padlocks, the Technical Manual adds that once a shackle has been installed and the kick plate hammered in place, the shackle cannot be changed.

Parts of a Master Lock Pro Series padlock

The Technical Manual's parts tables name seven components. For the 6121 Weather Tough padlock:

NKR (non key retaining): the key can be removed anytime. NRK (non removable key): the key can only be removed with the shackle locked. The 6121LJ takes the 293LJS6121 shackle; the 6840 and 7040 use the same 293S6121 shackle as the 6121. Other models are in the manual's parts tables.

Replacement cylinders: 295, 296 and 297

The price list sorts cylinders by base number:

• 295: 4-pin and 5-pin cylinders for rekeyable padlocks Nos. 21, 24, 25, 27, 101, 220 and 230
• 296: Pro Series padlocks (14 models listed, from the 6121 to the 7050)
• 297: Pro Series 6270 and 6271

The full number adds keying and cylinder type, as in the price list example 296 KA W6000. Our cylinder titles follow that order: 295KZW1 is a 295 cylinder, zero-bitted, W1, and 296KZW1 is the Pro Series version. The Technical Manual defines zero bitted as a cylinder combinated to keys cut to the manufacturer's reference number "0" bitting. It also notes that the 296W6000 cylinder is pinned with only 5 pins; for 6 pins, order 296W7000. The manual has the service procedures for exchanging or rekeying a cylinder.

Master Lock keys: blanks, key numbers and lost keys

• Key blanks in the price list, in boxes of 50: K1BOX for W1 cylinders (Nos. 1-6, 11 and others, and Pro Series with the W1 option), K27BOX for Nos. 21, 24, 25, 27, 101 and others, K6000BOX and K7000BOX for W6000 and W7000 cylinders. A key blank, in the manual's terms, has not yet been combinated or cut.
• Edge key control blanks are available to locksmiths only and controlled by contract, the price list says.
• For keyed padlocks, the price list gives key number ranges by lock model. According to Master Lock's support page, a locksmith or hardware store can use your key number for a new key; without it, there is no way for Master Lock to know which key opens the lock, and there is no master key that opens all Master Lock products. Master Lock does not supply replacement keys directly to customers.

Ordering keyed alike or master keyed padlocks

• To match a key you already have: Master Lock's support page says most lock models have an option to match an existing key and recommends confirming it for your model. Listings such as 1KALF2944 and 6271KAW7000-400K002 end with the key number (the price list's key range for W7000 cylinders is 400K001-594K569).
• Master keyed: the catalog says MK locks have to be ordered as such initially; locks are not automatically pre-set so that a master key can later operate them. When you add to an existing MK system, Master Lock asks for the master key code.

Master Lock parts and keys at The Builders Supply

• Master Lock - the brand page
• Pro Series shackles: 293S6121 and 293LJS6121
• Trap door for the No. 21 padlock: 0021-0372
• Key blanks for W1 cylinders: K1BOX
• Padlocks & Hasps - padlocks and hasps of several brands

Before you order

Have ready the model number with its letter codes, the shackle A and B you need, the cylinder type (W1, W27, W7000 and so on), and the key number if new padlocks must match old ones. Our customer support team is available Monday - Friday, 8 AM - 4 PM Central Time, at 1-888-800-7789 or [email protected].