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| | Safety Rules | | |  | | | BASIC SAFETY RULES FOR THE USE OF GRINDING WHEELS | | | The recommendations as set out below are only a summary of the most important precautions. All users must strictly comply with the safety instructions existing in the laws, regulations and technical standards of their country.
Rappold - Winterthur strongly recommend to visit the homepage of FEPA, the European Association of Grinding Wheel Manufacturers, who have an excellent summary of most relevant safety regulations.
| | | | | | | | | DO:
- Read the safety rules pertaining to your country. Consult the Rappold - Winterthur main catalogue’s safety section.
- Inspect products for defects when receiving and, again, prior to mounting.
Store grinding wheels in suitable rooms fitted with appropriate racks.
- Ensure that permissible RPM and/or surface speed in m/s or sfpm correspond to grinding wheel and machine intended for use.
- Use paper or plastic blotters between wheel and machine intended for use.
- Use torque wrench when tightening flange nuts.
- Inspect all guards and other safety features for proper functioning.
- Wear safety glasses.
- Start machine, step out of the way, and run machine at idle speed for 1 minute prior to cutting metal.
- Operate machine according to machine and wheel instructions.
| | | | | | | | | DONT:
- NEVER, EVER run a grinding wheel at higher surface speed (m/s or sfpm) than marked on the wheel.
- Never mount a vitrified grinding wheel without prior ring test. If dull sounds occurs, do not use wheel.
- Do not force a grinding wheel on flange, shaft or arbour.
- Do not operate a grinding machine with safety devices removed.
- Do not use a grinding wheel without wearing safety glasses.
- Do not side-grind with a wheel not intended for this purpose
| | | IF IN DOUBT, ASK YOUR WHEEL SUPPLIER - WINTERTHUR
| | | | | | | Ring Test of Vitrified Grinding Wheels | | | The wheel should be lightly tapped with a non-metallic hammer to the right and the left of the vertical centreline.
- Light wheels should be held on a finger or on a mandrel
- Heavier wheels should be placed on the floor, standing upright on their peripheral face. In the case of hard floor surfaces, place a wooden board between the floor and the wheel.
A crack-free vitrified wheel will emit a clear, bell-like ringing sound; a damaged wheel will sound dull. (Resin bonded wheels do not emit the same metallic ring as vitrified wheels).
Note: cracks are often invisible to the eye!
| | | | | | | | | | Mounting of Grinding Wheels | | | Prior to mounting, ring wheel to ensure that it is sound. Always use blotters between wheel and steel flange. For surface speeds of 50 m/s (10,000 sfpm) or higher, plastic blotters (polypropylene 0.5 mm thick) should be used. If paper blotters are used, moisten them with coolant prior to flange asembly. Paper blotters may require retightening after one day. Always use torque wrench for tightening flange screws.
As per ANSI B7.1-1988, Chapter 6.10.2, apllied torque should not exceed 20 foot pound (27 Newton metres/NM) unless specifically recommended by wheel manufacurer.
Use tightening sequence as illustrated below:
| | | | | | Applied torque specifically for and restricted to Winterthur standard specifications can be taken from the table below. These torque forces aplly only to OD grinding wheel, diamter 400 (16 inch) and lager, wheel width 25 mm (1 inch) and wider. The same spec in finer grit size or harder structure can, of course, be tightened with at least the same torque force
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Aluminium oxides "A" |
Torque in |
Torque in |
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3, 5 , 27, 29, 31, 42, 49, |
Newton-Meter |
"pound foot" |
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53, 54, 57, 58, 64, 68, 69, |
(Nm) |
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80, 81, 83, 85, 90, 93, 95 |
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A80 G8V |
20 |
15 |
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A60 H8V |
30 |
22 |
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A80 H8V |
30 |
22 |
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A80 H13VPMF |
30 |
22 |
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A80 H15VP |
20 |
15 |
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A60 J7V |
30 to 40 |
22 to 30 |
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A80 J7V |
30 to 40 |
22 to 30 |
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A60 K5V |
40 to 50 |
30 to 37 |
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A80 K5V |
40 to 50 |
30 to 37 |
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A54 L6V |
40 to 50 |
30 to 37 |
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A80 L6V |
40 to 50 |
30 to 37 |
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A80 H13VPMF |
30 |
22 |
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A80 L15VPMF |
30 |
22 |
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A120 L15VPMF |
30 |
22 |
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Silicon Carbide: "C" |
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11C80 F13VPMF |
25 to 30 |
18 to 22 |
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11C320 F20VPLF |
30 to 40 |
22 to 30 |
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11C60 H5V |
30 to 40 |
22 to 30 |
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11C60 H15VP |
20 |
15 |
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11C80 J15VPLF |
25 to 30 |
18 to 22 | | | | | | | | Colour Coding According to Suface Speed | | | All wheels used above 35 m/s (7,000 sfpm) must be colour coded as per the illustration below:
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| Group Websites |
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| Subsidiaries |
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| Countries |
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| Switzerland |
| Tel |
+41 52 234 41 41 |
| Fax |
+41 52 233 33 70 |
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| Austria |
| Tel |
+43 42 42 41 8110 |
| Fax |
+43 42 42 41 811 700 |
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| Germany |
| Tel |
+49 7121 93 240 |
| Fax |
+49 7121 93 2424 |
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