PRML (Unified Threads) | Z-PRO Premium Thread Mills | YAMAWA

Product Features

•  The same PRML can process right and left hand internal threads by using the helical interpolating process.
•  Because it cuts at the first thread, it won't make the internal threads taper and the internal threads become highly accurate.
•  When cutting, the load on the tool is small and the tool life is long.
•  Cutting resistance is reduced by turning the tool counterclockwise and machining it from the top to the bottom with 1 pass cutting.

Cutting Data                          

Processing Conditions［9.0P1.75 M12×1.75］		Pitch diameter change graph
Workpiece Material	SCM440（30HRC）
Cutting Speed	100m/min
Feed per Tooth	0.06mm/t
Cutting Length	24mm
Bored Hole Size	φ10.3
Number of Passes	1Time
Machinery Type	Tapping center (BT 30)
Cutting Fluid	Water soluble cutting fluid, 20 to 1 dilution

Use the internal coolant supply for blind hole applications.

Instructions	Processing Conditions:
Use a counterclockwise spindle rotation for a left hand cutting tool. Process from top to the bottom like ② 〜 ③. The program can be created from our web site.	Workpiece Material	Cutting Speed （m/min）	Feed per Tooth fz （mm/t）
	Thermal refined steel 35 ～ 45HRC	40 ～ 100	0.02 ～ 0.05
	Thermal refined steel 25 ～ 35HRC	40 ～ 100	0.03 ～ 0.06
	Cast Iron　FC	40 ～ 100	0.02 ～ 0.05
	Ductile Cast Iron　FCD	40 ～ 100	0.02 ～ 0.05
	Alloy Steel　SCM	40 ～ 100	0.04 ～ 0.06
	High Carbon Steel S45C ～	40 ～ 100	0.04 ～ 0.06
	Medium Carbon Steel S25C ～ S45C	40 ～ 100	0.03 ～ 0.05
	Low Carbon Steel ～ S20C ／ SS400	40 ～ 100	0.03 ～ 0.05

◇ Tool feed speed calculation formula
Feed speed (mm/min) = fz x No. of flutes x Revolution speed x
(Nominal dia. of internal thread - Cutter dia. (Dc)) / Nominal dia. of
internal thread