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Steel swivel spindle with stop pin, satin chrome finish

Tuff Stuff

Tuff Stuff 4520 Swivel Spindle 9/32" x 4-3/4" 20 TPI Stop Pin

SKU CH-X5WX-BP8W0 MPN 4520

A steel swivel spindle with stop pin replaces Corbin Russwin #21 hardware

  • Lock keyingKeyed Different
  • Surface finishSatin Chrome
  • Sold asBox
  • Swivel spindle fits 9/32" square mortise locks
  • 4-3/4" length matches Corbin Russwin #21 replacement
  • 20 TPI threading ensures secure knob engagement
  • Steel construction resists wear in daily use
  • Stop pin prevents over-rotation for reliable operation

Steel Swivel Spindle With Stop Pin

The Tuff Stuff 4520 is a steel swivel spindle with stop pin built for door lock repair and replacement. It fits mortise locksets that require a 9/32 inch square by 4-3/4 inch long spindle threaded at 20 threads per inch. Installers and facility managers use it to restore latch operation on compatible hardware.

Threaded Length And Square Drive Limits

The 20 TPI thread pitch and 9/32 inch square drive fix the mechanical interface to matching lock bodies and lever handles. Only hardware designed for this exact thread count and square dimension will engage correctly. The stop pin adds a fixed rotational limit that the lock case must accommodate.

Direct Replacement For Corbin Russwin 21

This spindle replaces Corbin Russwin 21 in surface mount mortise locksets and other brands sharing the same specifications. The swap is worth it when the original spindle is worn, stripped or missing and the lock chassis remains sound. It is not for tubular latches, cylindrical locksets or any hardware using a different square size or thread pitch.

How it compares

Measured against everything we stock in Door Lock Sets & Deadbolts, at today’s prices. Recalculated every night.

Price $1.99
Cheaper than about 99% of the 2,145 comparable items (median $55.99).

Specifications

Product
Brand nameTuff Stuff
Model name4520
Size & build
Surface finishSatin Chrome
More details
Lock keyingKeyed Different

Questions about this item

What does the 9/32" square x 4-3/4" size mean for my lock installation?

The 9/32" square section fits standard mortise lock hubs while the 4-3/4" overall length spans typical door thicknesses; the stop pin prevents the spindle from sliding through the hub.

How does the 20 TPI threading affect the spindle fit?

The 3/8"-20 thread pitch matches the original Corbin Russwin #21 specification so the spindle engages the lock's threaded hub without cross-threading.

Will this swivel spindle replace a Corbin Russwin #21 directly?

Yes, the 4520 is manufactured as a direct replacement for Corbin Russwin #21 with identical 9/32" square dimensions, 4-3/4" length and 20 TPI threading.

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