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Bonus Tolerance

In GD&T, bonus tolerance is a modification of a GD&T tolerance that under certain conditions increases the tolerance, hence the term “bonus”.

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More specifically, when the maximum material condition (MMC) (or) Least material condition (LMC) symbol is used to modify a GD&T tolerance, bonus tolerance becomes available

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VIRTUAL CONDITION (OR) MAXIMUM ENVELOP GEOMETRY

= MMC(LARGEST SIZE) + GEO. TOL.

= 10.10 + 0.050

= 10.15 mm

BONUS TOLERANCE (When MMC applied, difference between MMC and actual size)

=10.10 – 9.90

=0.20 mm

TOTAL ALLOWABLE PART STRAIGHT

=STRAIGHTNESS GEO.TOL + BONUS TOL. = 0.050 + 0.20 =0.250 mm

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VIRTUAL CONDITION (OR) MAXIMUM ENVELOP GEOMETRY

= MMC(LARGEST SIZE) + GEO. TOL.

= 10.10 + 0.050

= 10.15 mm

BONUS TOLERANCE (When MMC applied, difference between MMC and actual size)

=10.10 – 9.90

=0.20 mm

TOTAL ALLOWABLE PART STRAIGHT

=STRAIGHTNESS GEO.TOL + BONUS TOL. = 0.050 + 0.20 =0.250 mm

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TOTAL ALLOWABLE PART STRAIGHT

=STRAIGHTNESS GEO.TOL + BONUS TOL.

  1. = 0.050 + 0.20 =0.250 mm
  2. = 0.050 + 0.15 = 0.200 mm
  3. = 0.050 + 0.10 = 0.150 mm
  4. = 0.050 + 0.05 = 0.100 mm

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BONUS TOLERANCE (When MMC applied, difference between MMC and actual size)

  1. =10.10 – 9.90 =0.20 mm
  2. =10.10 – 9.95 = 0.15 mm

2) =10.10 – 10.00 = 0.10 mm

3) = 10.10 – 10.05 = 0.05 mm

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Dia size Ø 12.0 +0.007 / -0.002

Internal feature condition

True position tolerance.

Bonus tolerance

11.998

MMC

0.010

No bonus tolerance

11.999

-.001

0.011

(+0.001 Bonus tolerance)

12.000

-.002

0.012

(+0.002 Bonus tolerance)

12.001

-.003

0.013

(+0.003 Bonus tolerance)

12.002

-.004

0.014

(+0.004 Bonus tolerance)

12.003

-.005

0.015

(+0.005 Bonus tolerance)

12.004

-.006

0.016

(+0.006 Bonus tolerance)

12.005

-.007

0.017

(+0.007 Bonus tolerance)

12.006

-.008

0.018

(+0.008 Bonus tolerance)

12.007

-.009

0.019

(+0.009 Bonus tolerance)

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Dia size Ø 12.0 +0.007 / -0.002

Internal feature condition

True position tolerance.

Bonus tolerance

12.007

LMC

0.010

No bonus tolerance

12.006

+.001

0.011

(+0.001 Bonus tolerance)

12.005

+.002

0.012

(+0.002 Bonus tolerance)

12.004

+.003

0.013

(+0.003 Bonus tolerance)

12.003

+.004

0.014

(+0.004 Bonus tolerance)

12.002

+.005

0.015

(+0.005 Bonus tolerance)

12.001

+.006

0.016

(+0.006 Bonus tolerance)

12.000

+.007

0.017

(+0.007 Bonus tolerance)

11.999

+.008

0.018

(+0.008 Bonus tolerance)

11.998

+.009

0.019

(+0.009 Bonus tolerance)