PACIFIC 41L40 is the free machining version of MOLY-KROME^®. The addition of a small amount of lead to the chemistry plus cold drawing increases the average machinability rating to 86%. This leaded grade can be heat treated the same as a standard 4140 to achieve similar hardness and strength. Impact toughness is somewhat lower for the leaded grade for hardnesses exceeding 35 HRC. 41L40 works well in screw machines. It is sometimes used in the as received condition but is normally heat treated prior to use.