What does 316L, inner and outer polishing 250# mean?
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I earnestly ask everyone to explain. What does 316L, internal and external polishing at 250# mean? Does 304-AP offer internal and external polishing as a service? What is internal and external polishing?
Could it mean 250# sandpaper? Please ask an expert to answer.
250# refers to 250 micro Inches (μin), that is 6.3μm, and it is an indicator of surface roughness.
It probably means 250 mesh
316L, with polished inner and outer surfaces; the roughness level should be 6.3
Polish Grade Comparison – Buffing Type (Emery Size or Grit Size), Ra (μm): 60# – 3.2a, 12.5s, 125 ▽▽; 180# – 1.6a, 6.3s, 63 ▽▽▽; 220# – 1.2a, 4.8s, 48 ▽▽▽; 250# – 0.8a, 3.2s, 32 ▽▽▽; 300# – 0.4a, 1.6s, 16 ▽▽▽; 350# – 0.25a, 1.0s, 10 ▽▽▽; 400# – 0.2a, 0.8s, 8 ▽▽▽▽; 600# – 0.1a, 0.4s, 4 ▽▽▽▽. We specialize in electrochemical polishing; we can handle mechanical polishing as well as electrochemical polishing of the inner and outer surfaces of pipes of various diameters. We are also capable of performing high-precision polishing tasks, including on-site polishing during the maintenance of polymerization reactors. Jinxi Chemical Machinery Group Co., Ltd. Polishing Factory – Address: No. 25, Huaji Street, Huludao City, Liaoning Province. Mobile phone: 13898980209. Contact person: Mr. Liang
250# is a way of indicating roughness.