Thumb Latch

Manufacturer: SRS Hardware

(2 customer reviews)

Updated Thumb Latches (TL 01) are used in single hung window applications where no balance system is present. Easily retrofits into existing windows, unobtrusive and sturdy. Installation tips below.
Locks available in 4 finishes: lacquered brass, oil rubbed bronze, satin nickel and polished nickel.
Sold individually and boxes of 20.
Singles from $12.57
Twenty Packs from $215.40


SKU: TL 01 Category:


Our Thumb Latch (TL 01) sash lock is an updated version of the old Babcock Catch originally patented in 1880. These clever locks are used in single hung window applications where no balance system is present. If you have an old home, you’ve experienced the vexing issue of how to hold the lower (operable) sash open. Owners have come up with myriad ways to prop their windows open from sticks to paperbacks (which inevitably end up falling out of the window and into the shrubs, never to be seen again).  These locks solve this problem forever!  Our TL 01 locks are easily retrofitted into existing windows (requiring the removal of one sash stop and the lower sash), are unobtrusive and permanent. Only the small “push-button” remains visible.

Note: use 3/4″ Forstner or Multispur bit to drill the hole into the jamb. As ever with tight fitting hardware or screws, a bit of Bowling Wax the threads is good practice and will ease installation.


Additional information

Weight N/A
Dimensions N/A

$12.57 – $240.00


1 item, 20 Pack

Package Includes

Packaged individually or 20 in a pack


Lacquered Brass, Oil Rubbed Bronze, Polished Nickel, Satin Nickel


Not available yet


SRS Hardware

2 reviews for Thumb Latch

  1. Farmer Mike, Connecticut (verified owner)

    The double hung windows on my 1740 farmhouse use old sash locks, which may be antique Babcock locks. Several have broken thumb levers, so I decided to replace the broken locks with the SRS TL 01 lock. The replacement process was easy, requiring a 3/4″ mounting hole, new window sash slot, and new sash stop slot. Because my windows are very old and fit loosely, the size of the catch pin on the TL 01 is a bit small to securely hold the window. The new lock works, but if the window shifts a bit, it may fall off the latch. (This is why I only gave it four stars.)

    I was impressed by the quality of the TL 01 latch and its smooth spring action. Support from SRS was quick and very helpful. This is a great product, backed by great support. Thanks!

  2. Jon E (verified owner)

    While renovating our old house we were delighted to find online SRS Hardware’s TL 01 reproduction thumb latch to match our existing late 19th century Babcock Lock window sash lock hardware. We ordered them in oil rubbed bronze. They were shipped immediately and arrived quickly. They are beautifully made, installed easily, and work perfectly. Thank you Justin!

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Installation Guide

Click below for the latch installation guide.

Download the Installation Guide

Technical Drawing

Includes all necessary dimensions for installation.

Download the Technical Drawing

""I am installing the Storm Window hardware from SRS Hardware and am so happy. This hardware is one of the few things that I have bought online that exceeds my expectations. I am pleased to have found a company for whom the word quality is more than mere marketing. "  Erik H"

-Storm Window Hardware
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