South Adams Machine Trades

South Adams Machine Trades

Rockwell Hardness Tester

Rockwell Hardness Tester

Donated by: Micromatic, LLC Berne, Indiana

Rockwell Hardness Tester

Main Parts

Crank Handle

Trigger Lever

Capstan Handwheel

Weights

Dial

Penetrator

Anvil

Light Switch

Dial Setting Wheel

Rockwell Hardness Tester

Penetrators

Rockwell Hardness Tester

Anvils

Preparation for Hardness Testing• Part must be clean and flat• Stone off any burrs• If surface is extremely rough, use Belt Sander to

smooth

• Part must be at least 10 times thicker than the estimated depth the penetrator will go• Example, if the Penetrator will go .015 deep, the

part must be at least .15 thick

• Do not check close to the edge of the part• Part size must be at least 2-2.5 times wider than the

penetrator indention diameter

Hardness is the resistance to PenetrationWhat is happening when we use the hardness tester?

Rockwell Hardness Tester

Step 1

Verify Crank Handle is towards the operator

Use Capstan Handle to lower anvil to provide enough room to get the part you are testing

between the Anvil and Penetrator

Rockwell Hardness Tester

Step 2

Place part on AnvilNote: part must be clean

and flat to check accurately. Stone off part and remove

scale prior to testing

Be careful NOT to hit the

Penetrator with your part

Securely Support any long parts while testing

Rockwell Hardness

TesterStep 3

Applying the Minor Load

Use Capstan Handle to raise Anvil and Part

towards Penetrator. BE CAREFULL!! Move

slowly towards penetrator

Raise

Anvil

Lower

Anvil

Rockwell Hardness Tester

Step 4Applying the Minor Load

Slowly raise the Anvil until the Small Pointer is

on the Black Dot

Note: Small Pointer will be in the vertical position

Black Dot

Large Pointer will make

several revolutions

while setting Small Pointer

Rockwell Hardness Tester

Step 5Applying the Minor Load

Once the Small Pointer is on the Black Dot, the

Larger Pointer should be somewhat vertical.

Black Dot

DO NOT worry about stopping the Large Pointer exactly on the

“Zero”

!!WARNING!!If you go past

“ZERO” do not back up!

If you do back up you have to start

over in a new location

Rockwell Hardness Tester

Step 6Zero the Dial

Use Dial Setting Wheel to move the Dial so the “Zero” lines up

with the Large Pointer.

Rockwell Hardness Tester

Step 7Zero the Dial

Small Pointer should still be lined up with the Black Dot

Verify that the “Zero” is lined up with the Large

Pointer

Rockwell Hardness Tester

Step 8Applying the Major Load

Press Down on Trigger Lever

Crank Handle will automatically move away

from operator

Weights will automatically

drop

Rockwell Hardness Tester

Step 9Getting the

Reading

Rotate handle back towards operator

Once the Large Needle stops moving…..

Rockwell Hardness Tester

Step 10Getting the

Reading

Material Hardness: 51Rc (51 Rockwell “C” Scale)

Use outer Black Numbers for the Rockwell “C” Scale

Notice The “C” above each number

Inner “Red” numbers are for Rockwell “B”

ScaleNotice the “B” above

each number

Rockwell Hardness Tester

Step 11Remove Part

Turn Capstan Handle Counterclockwise to lower

anvil to remove part

Always Protect Penetrator Point

Rockwell Hardness Tester

Step 12Turn Off Light Turn off Light

Switch when Complete

Round Part Hardness Compensation