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
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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?
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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
- Trailer Tie Down Anchors
- Hardware
- Torx Screw
- 2-1/2 Inch Long
- Redline
more information >
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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.