For Professional Grinding and Finishing: The Correct Surface Speed is Everything

If you talk to our technical team here at Abrasive Finishing Systems you will soon realise that we talk about the correct surface speed of a machine a lot. The question is why.

The simple truth is that abrasives are no different to any other cutting tool. If you use your abrasives at the wrong speed, at best they will underperform and wear out too quickly, at worst they just won’t do the job at all!!

So What is the Right Speed?

Below is a summary table showing the recommended / correct surface speed in metres per second.

Material to be Processed	Surface speed ms-1
	Stainless steel, tool steel, high speed steel	18 – 30
	Cast iron, carbon steel	25 – 45
	Non-ferrous metals, copper, brass	25 – 35
	Aluminium, zinc	18 – 30
	Hard and hardened steel	8 – 15
	Titanium and titanium alloys	10 – 25
	Glass, ceramic materials and stone	8 – 14
	Acrylics	5 – 14
	Plastic and rubber	10 – 18
	Wood	15 – 25
	Lacquers, varnishes	8 – 15

That is all well and good but in the real world most people work in rpm so we have also prepared a small guide below for commonly used machines.

Angle Grinders:

Material to be processed	4” / 100mm	4 ½” / 115mm	5” / 125mm	7” / 178mm
	Stainless steel, tool steel, high speed steel	3500 – 6000	3000 – 5000	2750 – 4600	1900 – 3200
	Cast iron, carbon steel	4800 – 8600	4100 – 7500	3820 – 6900	2650 – 4775
	Non-ferrous metals, copper, brass	4800 – 6700	4100 – 5800	3820 – 5350	2650 – 3700
	Aluminium, zinc	3500 – 6000	3000 – 5000	2750 – 4600	1900 – 3200
	Hard and hardened steel	1500 – 2900	1300 – 2500	1200 – 2300	850 – 1600
	Titanium and titanium alloys	1900 – 4800	1650 – 5800	1500 – 3800	1050 – 2650
	Glass, ceramic materials and stone	1500 – 1900	1300 – 2500	1200 – 2300	850 – 1600
	Acrylics	955 – 1500	830 – 1300	760 – 1200	530 –   850
	Plastic and rubber	1900 – 3500	1650 – 3000	1500 – 2750	1050 – 1900
	Wood	2850 – 4800	2500 – 5800	2300 – 3800	1600 – 2650
	Lacquers, varnishes	1500 – 1900	1300 – 2500	1200 – 2300	850 – 1600

Powerfile Machines:

Powerfile machines vary widely in terms of their performance capabilities. Most fixed speed machines operate at the equivalent of 32ms-1 whereas variable speed machines operate from 0 – 32ms-1. We have therefore given a recommendation below on whether fixed speed or variable is required for a particular material.

Material to be Processed	Machine Recommendation
	Stainless steel, tool steel, high speed steel	Variable speed
	Cast iron, carbon steel	Fixed speed
	Non-ferrous metals, copper, brass	Variable speed ideal.
	Aluminium, zinc	Variable speed
	Hard and hardened steel	Variable speed with low speed option
	Titanium and titanium alloys	Variable speed with low speed option
	Glass, ceramic materials and stone	Variable speed with low speed option
	Acrylics	Variable speed with low speed option
	Plastic and rubber	Variable speed with low speed option
	Wood	Variable speed with low speed option
	Lacquers, varnishes	Variable speed with low speed option