Press Specific Pressure

Press Specific Pressure – Metric Units

To calculate Specific Pressure on the die face:

P_s   =    Press tonnage ÷ container area

P_s   =    Press tonnage x 1000 / p (container ID)² / 4

where P_s is in kilograms/square millimeter and container ID is in millimeters (typically 3% larger than billet diameter.

Billet Dia. – in.	6”	7”	8”	9”	10”	12”	14”
Billet Dia. --mm	152	178	203	228	254	305	356
Container ID-mm	160	185	210	236	262	314	365
Container Area – mm2	20106	26880	34636	43744	53913	77437	104635
Press MTons ¯	Press Specific pressure on Die Face – kilograms/square millimeter
800	39.79
1000	49.74	37.20
1200	59.68	44.64
1400	69.63	52.08	40.42
1600	79.58	59.52	46.19	36.58
1800	89.52	66.96	51.97	41.15
2000	99.47	74.40	57.74	45.72	37.10
2200		81.84	63.52	50.29	40.81
2400		89.28	69.29	54.87	44.52
2600		96.73	75.07	59.44	48.23
2800			80.84	64.01	51.94
3000			86.61	68.58	55.65	38.74
3200			92.39	73.15	59.36	41.32
3400			98.16	77.73	63.06	43.91
3600				82.30	66.77	46.49
3800				86.87	70.48	49.07
4000				91.44	74.19	51.65	38.23
4500					83.47	58.11	43.01
5000					92.74	64.57	47.79
5500						71.03	52.56
6000						77.48	57.34
7000						90.40	66.9

Notes:

1.    Many experts recommend operating with Specific Pressure (die face pressure) in the range of 60 to 80 kilograms/square millimeter.

2.    Many North American extruders operate in the range 50 to 60 kg/mm2.

3.     The optimum range of Specific Pressure will also depend on extrusion practices and the type of profile or bar being extruded.