I purchased a set of ER collets and collet chuck holders. The runout accuracy was excellent and met our quality standards. However, the hardness of the hardened taper section does not appear to meet the manufacturer's stated HRc 58-62. When tested with a file of approximately HRc60, the surface could be filed down. By comparison, Japanese-made holders such as BIG and NT show no effect at all from the same file — it simply slides off. This is somewhat disappointing, but given the price, I think it's a reasonable trade-off in build quality.
Respuesta del proveedor:
Thank you for your feedback and trust in Shengda! We're glad to hear that the runout accuracy met your expectations. We always strive to provide reliable products at competitive prices and truly appreciate your support. We look forward to serving you again!
14 Oct 2026