bottom pulley

Garage Door Pulley Comparison for Cable Fit Reference Standard: Relevant material and performance testing standards may include dimensional inspection practice, visual coating inspection, and general corrosion evaluation logic such as ASTM B117 for salt spray exposure context, without treating any unlisted salt spray result as verified for this catalog item. Short Answer A garage door pulley should not be judged by product name alone. The catalog confirms BT-901 as a 4 inch galvanized pulley with 1.8 mm thickness, BT-902 as a 3 inch galvanized pulley with 1.5 mm thickness, and BT-904 as a galvanized bottom pulley with 3.75 mm bracket thickness; these verified points are enough to compare cable direction, … 続きを読む