grinding Flashcards
wheel guards should extend what degrees past the vertical
30 to 45 degrees
three basic types of surface grinders
horizontal spindle with reciprocating table
horizontal spindle with rotary table
vertical spindle with either reciprocating or rotary table
what tolerance can a surface grinder get
less then 0.0001
grinders typically run at what rpm
1750 rpm
what grit is on the left side of a grinder
coarse
what is truing on a grinder
getting the grinder wheel flat or straight
4 most common natural abrasives
Crocus
Corundum or aluminum oxide
Emery
Diamond
What are the three colours of aluminum oxide disks
Grey
Lighter grey
White
Strength/weakness of grey aluminum oxide disk
Tougher and less brittle
Strength/weakness of light grey aluminum oxide disk
Pure, more brittle and not as tough
Strength/weakness of white aluminum oxide disk
The purest and the most brittle
What are silicon carbide disks made from
Silica sand
Coke
Sawdust
Green silicon carbide disks are used for what
Grind cemented carbides
Ceramics
Hard materials
Black silicon carbide disks are used for what
Grind cast iron and soft non ferrous metals
4 properties of abrasives
Hardness
Heat resistances
Toughness
Friability
CBN stands for what
Cubic boron nitride
Grit sizes range from
40 to 600
parts of a grinder
nut
outer/inner flange
blotter
bushing
shaft
the stronger the bond/grade the
softer the material
3 common bonds
vitrified
resinoid
rubber
what does load mean in abrasives
when your grinding and the material gets clogged in the abrasive
what would a 15 be grain density
open structure
Toughness in abrasives is what
Ability of material to resist impact and pressure
Toughness in abrasives is what
Ability of material to resist impact and pressure
Heat resistance in abrasives is what
Ability of material to withstand the heat of grinding without dulling
Hardness in abrasive is what
Ability to scratch or penetrate another material
Friability in abrasives is what
Ability of material to fracture under stress. Grain breaks off and presents new cutting edges
What do the 6 positions mean when talking about the marking system
1 abrasive type
2 grain size
3 the grade
4 structure or density
5 bond type
6 manufacturers record
What should the gap between the spark guard and the periphery of the wheel be
1/16 and 1/4 inch
What does the blotter do
Protects the flanges from the abrasive grit
Displays important information about the wheel
What is dressing
Removes the top layer of abrasive particles to expose the fresh ones beneath
What are the 4 dressers
Mechanical
Abrasive stick
Abrasive wheel
Diamond
Flanges should be at least what diameter
1/3 the diameter of the wheel
