How Many Threads Per Inch Does the 2-1/2" Long Torx Trailer Floor and Wall Liner Screw Have?
Updated 09/08/2025 | Published 06/04/2025
Products Featured in This Question
Question:
On the product information page 2-1/2" Long Torx Trailer Floor and Wall Liner Screw for ACQ Treated Wood Part Number: TFX250ACQ the 2-1/2” 1/4” screws are said to have 21TPI, threads per inch. That’s a really unusual thread pitch. Is it actually 20 TPI, or is there a reason you do 21TPI?
asked by: Mike
Expert Reply:
Hey Mike. I checked with the manufacturer and the 2-1/2" Long Torx Trailer Floor and Wall Liner Screw for ACQ Treated Wood item # TFX250ACQ does have 21 threads per inch.
These screws are specially designed for use on Alkaline Copper Quaternary wood. They have a blunt tip so you'll want to drill a 7/32" pilot hole.
You'll need a TRX 30 bit to install them like our Torx Head Screwdriver Bit item # TX430-1.
Are you looking to replace screws in your trailer floors or are you swapping out the flooring entirely?
(click to enlarge)
Product Page this Question was Asked From
2-1/2" Long Torx Trailer Floor and Wall Liner Screw for ACQ Treated Wood
- Accessories and Parts
- Tie Down Anchors
- Hardware
- Torx Screw
- 2-1/2 Inch Long
- Redline
more information >
Continue Researching
- Q&A: Torx Screws For Replacing 2x6 Boards On Big Tex Utility Trailer
- Q&A: Does TecNiq Round Side Marker Light TN54TR Come with Grommet
- Q&A: Will The Thule Kit Cover TH98SA Fit Thule Evo Fixpoint and Edge Fixpoint Roof Rack Feet?
- Q&A: Recommendation For Screws To Attach Pressure Treated Decking To a Flat Trailer
- Q&A: Are the 2-1/2" Long Torx Trailer Floor and Wall Liner Screws for ACQ Treated Wood Sold Individually
- Q&A: Coating on the Redline 2-1/2" Long Torx Trailer Floor and Wall Liner Screw # TFX250ACQ
- Q&A: How Many Screws Are Included with the 2-1/2" Long Torx Trailer Floor and Wall Liner Screw
- Article: Trailer Drum Brakes vs. Disc Brakes: Making the Decision
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Trailer Lighting Requirements
- Article: Our Team Picked The Best Camping Gear of the Year - Here Are Their Top Choices
- Article: How to Tell the Weight Rating of a Trailer Axle
- Article: Breakaway Kit Installation for Single and Dual Brake Axle Trailers
- Article: Aluminum, Galvanized, or Painted: Which is Best for Your Boat Trailer?
Jerred H.
9/8/2025
Hey Mike, did you decide to use the 2-1/2" Torx screws for your trailer floors, or are you planning to replace the flooring completely? I'm curious to know how it worked out for you, as it could help others with similar projects.