PVC extruding tube used for building electric wires passed.
The outer diameter is 20mm, and the thickness is 1.3mm or 1.4mm, the length is fine. Just consider the container length for easy transportation.
We can make the code and company name(custom, need the authorization) on the tube by your requirement.
What ASTM F436 Flat Washers Are?
Content ASTM F436 American steel structure washers classification, generally using 45# steel plate stamping processing. ASTM F436 Structural Washers are designed for use with A325