Stiff Link Thumb 5-tooth 545 mm (21 in): 437-2774

SL Thumb 545 mm (21 in)

Stiff Link Thumb


Cat® Stiff Link Thumbs are the ideal add-on to add versatility to your Cat machines. Designed for specific excavator and bucket combinations, they help you take on more materials without compromising fuel efficiency. We built them to upgrade your machine to handle larger, bulkier materials.

Increase the Productivity of Your Machine

  • Two static working positions at 90° and 105°
  • Closed face design holds fine materials better, provides better retention when working in loose material, and prevents material from packing in the frame.
  • Expanded machine compatibility range due to a lighter design
  • Increase the productivity with periodic use where a bucket or rake alone would fall short

More Versatility More Work Done

  • Works with bucket or rake to grab, pick, sort, and move materials
  • Stiff Link Thumbs are universal to across range of bucket sizes, making them easier to pair to buckets in a mixed fleet
  • Get the best thumb for your tasks. With three tine configurations, select the best option for a wide or narrow grip, shorter center times for straddling the boom during transport.
  • Managing multiple attachments for a fleet is easier with a coupler system. Select thumb models are compatible with Cat Pin Grabber Couplers, allowing for machines of similar sizes to share thumbs and other attachments.

Simple to Operate

  • Patented alignment system allows for one person to easily deploy or store the thumb
  • Folds against machine boom for easy storage during travel or other activities
  • Simple installation, maintenance, and overall operation make thumbs a simpler, more affordable owning and operating choice than grapples

Boost Efficiency and Productivity with Integrated Technology

  • Never waste time looking for your thumbs again. Cat asset tracking is available for your attachments or anything in your fleet you need to track.
  • Track your entire fleet of attachments and machines from one source. View thumbs with asset tracking within VisionLink® alongside Product Link™subscribed equipment.
  • Keep your assets secure. Thumbs with an asset tracker send an alert if they leave an easy-to-setup site boundary.

  • Specs
  • Docs



Long Name:
SL Thumb 545 mm (21 in)
Stiff Link Thumb 5-tooth 545 mm (21 in): 437-2774
Number of Teeth/Tines
Stored Height
20.39 in / 518 mm
Overall Width
21.4 in / 545 mm
715 lb / 324 kg
59.34 in / 1507 mm
Two static working positions at 90° and 105°
Tines Included
Machine Class
11 to 19 ton excavators
Interface Type
Pin Grabber