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Straight steel spindle with satin chrome finish, 9/32 inch square by 4 inch long, 20 threads per inch

Progressive Hardware Co., Inc.

Progressive Hardware Co., Inc. 44-20-4 Straight Steel Spindle 9/32" Square x 4" Long 20 TPI door lock

SKU CH-D10M-TW0AT MPN 44-20-4

Straight steel spindle with 9/32" square profile, 4" length and 20 TPI threading replaces worn door-knob spindles

  • FinishSatin Chrome
  • Selling UnitEach
  • KeyingKeyed Different
  • Straight spindle design fits vintage door knobs directly
  • 9/32 inch square by 4 inch length matches original hardware
  • 20 threads per inch on both ends ensures secure fit
  • Steel construction provides lasting strength for daily use
  • Unthreaded centre section allows smooth knob operation

Replacement Straight Spindle

The Progressive 44-20-4 is a straight steel spindle measuring 9/32" square by 4" long with 20 threads per inch on both ends and an unthreaded centre section. It is manufactured as a direct replacement component for vintage and current door knob assemblies. Homeowners and maintenance professionals use it to restore operation to mortise locks where the original spindle has worn or broken.

Compatibility Upgrade

This spindle replaces damaged or missing originals in locksets from brands including Corbin Russwin, Yale, Marks, Norwalk, National, Baldwin and Progressive hardware. The jump is worth it when an existing spindle is stripped, bent or too short to engage both knob hubs securely. It is not for buyers who need a swivel or offset spindle, or for modern tubular latchsets that require a different cross-section or thread pitch.

Dimensional Limits

The 9/32" square profile and 20 TPI threading define the mechanical interface, so the spindle only fits lock bodies and knob hubs machined to those exact specifications. The 4" overall length sets the maximum door thickness it can bridge when both knobs are fully seated. Installers must verify that the lock case accepts a straight, unthreaded centre section before purchase.

Highlights

  • Straight spindle design fits vintage door knobs directly
  • 9/32 inch square by 4 inch length matches original hardware
  • 20 threads per inch on both ends ensures secure fit
  • Steel construction provides lasting strength for daily use
  • Unthreaded centre section allows smooth knob operation

Specifications

BrandProgressive Hardware Co., Inc.
Model44-20-4
FinishSatin Chrome
Selling UnitEach
KeyingKeyed Different

Questions about this item

What door thickness does the 4" long spindle suit?

The 4" length fits standard interior doors up to about 1-3/4" thick; measure your existing spindle before ordering.

How do I thread the spindle into vintage knobs without cross-threading?

Start each 20 TPI end by hand for at least two full turns before using pliers; the unthreaded centre prevents over-tightening.

When should I replace this steel spindle?

Replace if the square section rounds off, threads strip, or the knob develops excessive rotational play.

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