... *M3/M42 hign speed steel hole saws are rugged for cutting tools designed to cut accurate holes in machinable materials up t038mm ... 300mm in diameter *they can use in portable electric,air tools,drill presses.lathes,boring mills,milling machines or any other ... 4/6 vari-pitch tooth design and are recommended for cutting steel and cast iron pipe,steel plates,aluminum.copper,brass ...