Surface roughness examples in 80ｍｍ-deep-hole drilling
(hole dia. 3.0 mm, hole depth 80 mm)

surface roughness example
drilling:　　　Ra 0.67 – 1.83
gun-drilling:　Ra 0.43
reaming:　　Ra 0.13

160ｍｍ-deep-hole drilling with bore polishing

Hole dia.1.7 mm, depth 160 mm, surface roughness Ra 0.015

small-diameter deep hole drilling

We provide minimum deviation from straightness for small-diameter deep hole drilling, for example; deviation from linearity ≦ 0.05mm, inner surface roughness ≦ Ra 0.4 for hole dia. 0.1 mm, hole depth 2.5 mm.