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A serration ring made of zinc die cast is inserted into the lever body made of plastic. They also realize sufficient strength for fitting with metal thread serration.
A rich variety of thread sizes from M3 to M12 are available.
There are three types of combinations of thread part materials / surface treatments:
LEM ----Made of steel / ferrosoferric oxide film (black)
LEME ----Made of steel / electroless nickel plating
LEMS ----Made of stainless steel
LEME has electroless nickel plating applied to its thread part made of steel to enhance its corrosion resistance.