Peter Halle said:
I tried the arbor nut from my grinders on the RAS 115 and they are too big.
When it comes to angle grinders, it appears that the fixing that secures the grinding wheel or wire brush to the spindle of the grinder varies between Europe and the USA.
For example, here we have the Bosch 4-1/2" Angle Grinder, Model 1800
Specifications from the Bosch USA website are:
Amperage: 7.5
Certifications: cULus
Length: 11-1/4"
Max. Motor HP: 1.1
No Load RPM: 11,000
Rating: 120 V AC/DC
Spindle Thread: 5/8" - 11
Weight (lbs.): 4.3
Wheel Diameter: 4-1/2"
And here we have the Bosch GWS 8-115 Professional, which is a grinder with very similar specifications from Europe:
Specifications from the Bosch UK website are:
Rated power input 800 W
No-load speed 11.000 rpm
Power output 500 W
Grinding spindle thread M 14
Disc diameter 115 mm
Rubber sanding plate, diameter 115 mm
Wire cup brush, diameter 70 mm
Length 286 mm
Height 106 mm
Weight without cable (EPTA standard) 1,9 kg
Notice how the spindle on the UK model has a M14 thread, whilst the model for the US market has a 5/8"-11 thread
The Festool RAS115 has an M14 thread, just like most other similar European angle grinders. It's therefore not possible to directly attach US cup brushes and other accessories with the 5/8"-11 thread, which is the standard in the USA. 5/8" is approx 16mm, which is why the thread on US attachments is too big for the M14 (Metric 14mm) spindle.
Also note that the speed of both of these angle grinders is 11,000rpm, compared to the RAS115 which is much slower at 1,500 - 4,000 rpm.
It's also interesting to see the different method of expressing the power of European and USA power tools. Bosch USA say their grinder is 1.1HP and 7.5A, whereas in Europe the power is expressed in Watts with no mention of Amps or Horsepower.
Forrest