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Straight steel spindle with satin chrome finish

Tuff Stuff

Tuff Stuff 4424 9/32" Square x 4" 20 TPI Door Lock Spindle

SKU CH-KMCT-EKB2S MPN 4424

Straight steel spindle measuring 9/32 inch square by 4 inches long with 20 threads per inch for vintage door knob replacement

  • Lock keyingKeyed Different
  • Surface finishSatin Chrome
  • Sold asBox
  • Straight spindle fits vintage knobs from Corbin Russwin and Yale
  • 9/32 inch square by 4 inch length matches original hardware
  • 20 threads per inch on both ends ensures secure engagement
  • Steel construction provides lasting strength for daily use
  • Satin chrome finish resists corrosion and blends with existing trim

Replacement Spindle for Vintage Knobs

The Tuff Stuff 4424 is a straight steel spindle made for vintage door knob sets. Its 9/32" square profile and 4" length match legacy hardware from brands such as Corbin Russwin, Yale and Baldwin. The satin chrome finish resists corrosion while blending with period trim. Installers and restorers can fit it without modifying original mortise locks.

Threaded Ends With Unthreaded Centre

Both ends carry 20 threads per inch for secure engagement with knob roses or escutcheons. The unthreaded centre section prevents binding during operation and allows smooth rotation through the lock body. Steel construction resists bending under repeated leverage from heavy doors. The straight profile suits mortise locks that do not accept swivel or offset spindles.

Direct Substitute for Worn Originals

This spindle replaces stripped, bent or corroded originals in residential and light commercial doors. The upgrade is worth it when the existing spindle no longer drives the latch reliably or when a knob spins freely without retracting the bolt. It is not for modern tubular latchsets that require a smaller square or a different thread pitch, nor for handlesets needing a split or half spindle.

How it compares

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

Price $1.40
Cheaper than about 99% of the 2,145 comparable items (median $55.99).

Specifications

Product
Brand nameTuff Stuff
Model name4424
Size & build
Surface finishSatin Chrome
More details
Lock keyingKeyed Different

Questions about this item

Does the 20 TPI threading generate any heat or noise during daily door operation?

No — the spindle is a passive steel component with 20 threads per inch on each end and an unthreaded centre; it produces no heat or sound during normal use.

What existing hardware must I already have for the 9/32" square spindle to fit?

You need a mortise lock or latch with a 9/32" square hub and standard 20 TPI threads on both sides, typical of Corbin Russwin, Yale, Marks, Norwalk, National, Baldwin or vintage knob sets.

Will the 4" straight spindle work with older mortise locks that have a thicker door section?

The 4" overall length suits most vintage mortise locks; if your door is unusually thick you may need a longer spindle, but the 9/32" square and 20 TPI match the original hardware.

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