Sunday, 14 September 2014

Hi Grinding Advice You Probably Didn’t Know!.

Hi Grinding Advice You Probably Didn’t Know!.

Here are some additional reasons why you should not even need gloves when working on grinders and grinding machines.

Issue: 

"There are sharp edges or burrs that will cut me if I hold the part. The grinding will be to remove the burrs."

Response: Use a file to knock down the burrs so that you can safely hold the part for grinding. Or use leather finger cots to grip the part for grinding.

We permitted these for use on belt grinders for holding small parts.

Issue: "The part gets too hot to hold."

Response: Then you are grinding wrong. Here is a list of some of the things that can go wrong by letting the heat of grinding get out of control:
  • Remove the temper from Steel. Especially on tools, loss of temper means loss of tool hardness and edge life. A drop from Rc63 to about Rc48 for a couple of tenths (0.0002-0.0005) can contribute to side wear and edge failure.
  • Crazing or checking on Carbide can be caused by burning during grinding.
  • Work Hardening. Overly shiny surfaces are usually the clue that work hardening has occurred.
  • Creation of untempered martensite.
Untempered martensite can be formed in high carbon and alloy steels by getting high surface temperature from grinding- red heat- then quenching in water.
  • Untempered martensite is very brittle and reduces toughness.
  • Keeping the work cool continuously while grinding is an important aspect of preventing damage to work, the wheel, and injury from occurring to the worker. Hogging off material and infrequently quenching is a great way to destroy a tool by grinding.
  • Water needs to be plentiful to absorb the heat from grinding, and frequently used to reduce heat buildup in the work.
  • Take multiple small passes and cool in between in a large bath of water while grinding to minimize heat build up.
Of course, wearing the required PPE, making sure the grinding wheel is properly dressed, all guards are in place and properly adjusted are also key to safe grinding in our shops.

Bottom line: If the work is too hot for your fingers, it may be approaching the danger zone regarding loss of mechanical properties and function in end use.


Hi Popular Posts

Search Hi E Community

Hi Definitions of disaster types.

Sudden natural

Long-term natural

Sudden human-made

Long-term human-made

Avalanche

Cold wave

Earthquake

Aftershock

Floods

Flash flood

Dam collapse

Volcanic eruption

Glowing

avalanche

Heat wave

High wind cyclone

Storm

Hail

Sand storm

Storm surges

Thunder storm

Tropical storm

Tornado

Insect infestation

Landslide

Earth flow

Power shortage

Tsunami and tidal wave

Epidemics

Drought

Desertification

Famine

Food shortage or crop failure

Structural collapse

Building collapse

Mine collapse or cave-in

Air disaster

Land disaster

Sea disaster

Industrial/technological accident

Explosions

Chemical explosions

Nuclear explosion or thermonuclear explosions

Mine explosions

Pollution

Acid rain

Chemical pollution

Atmosphere pollution

Chlorofluoro-carbons (CFCs)

Oil pollution

Fires

Forest/grassland fire

National (civil strife, civil war)

International (war-like encounters)

Displaced population

Displaced persons

Refugees