Tool Setting

The tool diameter can be adjusted in the following manner for std. SH, LG, UNL and EXT series tools.Retract the spring loaded adjusting coller and rotate the threaded bearing coller either on + or - side. This will alter the position of tapered mandrel (or) race in relation to the tapered rolls, thereby changing effective tool diameter to increase (+) or decrease (-) accordingly.

Now set the tool diameter to where the rolls slide snugly over the prepared   surface.... Similar to Plug or Ring gauging a part. Adjust the tool by rotating the bearing coller as above to 1 division marked (0.0025 mm) on. (increase for I.D. Tools and reduce for O.D. Tools). Select the Tool's RPM and Feed rates as per the chart. Trial run the prepared parts and inspect the finish. Adjust the tool by increase/decrease the tool dia by 1 or 2 divisions till the desired finish is achieved.

How To Get Good Results

Burnishing is a Cold rolling process without actual removal of metal. Hence it is important to control the pre burnishing stock allowance and surface roughness 10 desired levels to obtain a best burnished surface finish. The surface finish generally obtained for various operations are given below.

 

Operation

Burnishing

Honing

Ground

Ream

Bore

Turn

Surface Finish (Ra)

0.05-02

0.1-02

0.2-04

0.4-0.6

0.8-1.2

1.5-2.00

Diameter Change mm

0.025

0.063

0.063

0.250

0.50

0.95
 

Stock Allowance Chart

DIAMETER

STOCK ALLOWANCE


5 - 12 mm
13 - 25 mm
26 - 50 mm
50 and above


0.01 - 0.02 mm
0.013 - 0.020 mm
0.013 - 0.025 mm
0.018 - 0.035 mm
NOTE : The parts should be de-magnetized prior to roller burnishing.

Speed & Feed Chart

  Tool Dia   
    (mm)

   Speed 
   (RPM)     

   Tool Feed Rate 
       (mm/rev)

      5-10

1020-4300

0.25-0.50

     10-15

610-3100

 0.45-0.90
15-20 500 -1800 0.75-0.90
20-25 380-1500 0.8-1.4
25-30 300 -1000 1.2-1.7
30-35 275 -900 1.6-2.0
35-40 235 -825 1.9-2.4
40-45 215 -700 2.1-2.6
45-50 190-610 2.8-3.2
50-55 170 -540 3.4-3.9
55-60 160-510 3.8-4.2
60-65 150 -460 4.2-4.5
65-70 140 -435 2.2-2.4
70-75 125 -400 2.5-2,6
75-90 110-380 2.5-2.3
90-100 95 -325 3.2-3.9
100-115 85 -285 3.9-4.6
115-130 75 -225 4.5-5.2
130-140
& Above		 70-210 5.8-5.9

Trouble Shooting

PROBLEM

CAUSE

REMEDY
Burnishing finish not achieved Wrong tool setting Correct the tool setting as explained
Burnished bore having taper and ovality Pre-burnishing condition not maintained Check pre burnished part for taper and ovality and correct pre burnishing operation such as drilling, turning, reaming, boring to desired tolerances.
Excessive heat produced during burnishing Inadequate flow of coolent Use continuous flow of proper coolents
Poor life of Rollers Inadequate flow of coolent Improper Speed and feed selection Incorrect burnishing allowance Use continuous flow of proper coolents Select proper speed and feed as per chart Check pre burnishing dimension and correct pre burnishing operation to obtain desired dimension.
Poor surface finish after some usage of tool Uncleaned tool Wear out of rollers Clean the tool properly after use and oil before storage. Replace worn out rollers.
Breakage of cage and guide Rollers Incorrect burnishing allowance Excess load Check and correct burnishing allowance Set the tool as per the guide.

Surface Finish Chart

Ra

R max

Rz

N

 Triangle Mark
0.0013a
0.025a
0.05a
0.10a
0.20a		 0.05s
-.018
0.2s
0.4S
O.QS		 0.05z
0.1z
0.2z
0.4z
0.8z

N1
N2
N3
N4

 ****

0.40a
0.80a
1.6a

1.6S
3.2s
6.3s

1.6z
3.2z
6.3z

N5
N6
N7

 ***

3.2a
6.3a

12.58
25.0S

12.5Z
25.0z

N8
N9

 **

12.5a
25a

50s
100s

50z
100z

N10
N11

 *

50a
100a

200s
400s

200z
400z

 N12 -

NOTE : Rt = Ra x 4