Professional Razor Edge Thinning Scissor Adjustable Screw with Fixed Finger Rest. Available Sizes. 4 in, 4.5 in Details. Razor Edge thinning scissors made of Japanese stainless steel J/2 - 420, HRC° (hardness) 52° - 55°. Also available in 440C HRC° (hardness) 60° - 65°. Available in fix, limitation, adjustable and hand adjustable screws with and without leaf spring.