factory inspection

Garage Door Spring Bumper: Detailed Explanation Reference Standard: Relevant material and performance testing standards include ASTM A90/A90M for zinc coating weight on galvanized steel and ISO 9227 corrosion testing in artificial atmospheres. Short Answer A garage door pusher spring, also called a spring bumper, should be evaluated by how it behaves after repeated closing impact, not only by its catalog appearance. The available product data identifies Spring Bumper and Small Spring Bumper items with 2.5mm thickness and galvanized finish, so the key buying focus should be rebound stability, surface wear resistance, dimensional consistency, and shipment-level inspection. For buyers comparing a garage door spring bumper, the most useful question is not … 続きを読む