How do you calculate line speed on an extrusion line?

Divide good extruded length by elapsed run time for raw speed, then multiply by cooling and sizing efficiency. 1,800 ft over 60 min is 30 ft/min raw; at 92% efficiency the usable speed is 27.6 ft/min.

Why does wall thickness limit line speed?

Thicker walls carry more heat and take longer to cool below the freeze line, so the calibration and cooling stages cap how fast you can pull without distorting the section.

What is cooling and sizing efficiency?

It is the fraction of raw haul-off speed you can actually sustain while holding dimensions. If the tank can only fully set 92% of the theoretical speed, your effective line speed is 27.6 ft/min, not 30.

What happens if I run faster than the effective line speed?

You risk under-cooled walls, ovality on pipe, sink marks on solid profile, and internal stress. The part may pass at the gauge but fail later or bow after cooling.

How do I increase sustainable line speed?

Add cooling tank length, lower water temperature, improve vacuum sizing, or optimize melt temperature so less heat needs removing — each raises the efficiency factor rather than the raw speed.

Line speed vs output rate — which should I watch?

Line speed sets the instantaneous pace and dimensional risk; output rate grades the whole run against plan. Use line speed to dial in the setpoint and output rate to grade the shift.

Plastics Extrusion - Pipe, Film & Profile calculator

Line Speed By Wall Thickness Calculator

Line Speed By Wall Thickness tells you how fast usable product actually leaves the line in feet per minute once you account for cooling and sizing efficiency. On pipe and profile lines, thicker walls need more residence in the cooling tank and calibration sleeve, so the theoretical haul-off speed and the sustainable speed diverge. Process engineers and line operators use this to set haul-off rates that hold wall spec without outrunning the cooling capacity. Push line speed past what the tank and vacuum sizing can handle and you get oval pipe, sink marks, and stressed walls.

What this calculator does

Estimate usable haul-off line speed from produced footage, run minutes, and a wall thickness or cooling efficiency allowance.
Use it when pipe wall thickness, sheet gauge, or profile section size changes and the team needs a realistic line speed.
It computes raw line speed as good length divided by run time, then derates it by cooling and sizing efficiency to give a sustainable, in-spec speed.

Formula used

Raw line speed by wall thickness = good extruded length ÷ elapsed run time
Effective line speed by wall thickness = raw result × cooling and sizing efficiency

Inputs explained

Good extruded length:
Elapsed run time:
Cooling and sizing efficiency:

How to use the result

Use it when setting or validating haul-off speed for a given wall thickness, especially when commissioning a new profile or troubleshooting dimensional drift.
The efficiency factor is a single lumped derate — it does not model tank length, water temperature, or vacuum level, so it guides rather than replaces a proper cooling calculation.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The producer price index for aluminum mill shapes stands at 404.859 (BLS, May 2026), up 36.8% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The producer price index for plastic resins and materials stands at 319.371 (BLS, May 2026), up 19.5% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 3,569 primary metal manufacturing establishments employing about 354,911 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate line speed on an extrusion line? Divide good extruded length by elapsed run time for raw speed, then multiply by cooling and sizing efficiency. 1,800 ft over 60 min is 30 ft/min raw; at 92% efficiency the usable speed is 27.6 ft/min.
Why does wall thickness limit line speed? Thicker walls carry more heat and take longer to cool below the freeze line, so the calibration and cooling stages cap how fast you can pull without distorting the section.
What is cooling and sizing efficiency? It is the fraction of raw haul-off speed you can actually sustain while holding dimensions. If the tank can only fully set 92% of the theoretical speed, your effective line speed is 27.6 ft/min, not 30.
What happens if I run faster than the effective line speed? You risk under-cooled walls, ovality on pipe, sink marks on solid profile, and internal stress. The part may pass at the gauge but fail later or bow after cooling.
How do I increase sustainable line speed? Add cooling tank length, lower water temperature, improve vacuum sizing, or optimize melt temperature so less heat needs removing — each raises the efficiency factor rather than the raw speed.

Last reviewed 2026-05-12.