Fits and Tolerances

5/24/2018 Fits and Tolerances

1/17

4

Fits and Tolerances

(tolerance)

(shaft) (hole)

ISO (InternationalStandard Organization)

4.1

4.1.1 (shaft) (hole)

19


2/17

20 4. FITS AND TOLERANCES

4.1:

4.1.2

4.1 (basic size) (maximumlimit) (maximum material limit, MML)

(minimum limit) (minimum materiallimit, LML) (MML) (LML)

(deviation) (actual size) (basicsize) ()

(upper deviation) (lower deviation) (fundamental deviation)

4.1.3 (tolerance)

()

4.2 (fit)

(clearance fit), (transition fit), (interference fit)


3/17

4.2. (FIT) 21

4.2: clearance fit

4.3: transition fit


4/17


4.4: interference fit

4.2.1 clearance fit 4.2 (minimum clearance) (maximum clearance)

, 4.1 4.4

4.2.2 transition fit 4.3

(maximum clearance) maximuminterferance

4.2.3 interferance fit 4.4 (press) 10-20 minimum interferance maximum interferance

4.2.4 Allowance

clearance fit (minimum clearance) allowance positive allowance


5/17

4.2. (FIT) 23

4.5: Grade of Tolerance [?]

transition interferance fit negative allowance allowance (maximum material limits, MML)

4.2.5 Grade of Tolerance ISO (grade of tolerance) 18 tolerance 4.5 1.6 ITO1, ITO, IT1, IT2, up to IT16

grade of tolerance

4.2.6 Bilateral and Unilateral limits

(bilateral) (unilateral) (maximum and minimum limits) (basic size) (maximum and minimum limits) (basic size)

4.2.7 (Fundamental Deviation of Toler-ance)

(fundamental deviation) (tolerance zone)


6/17


4.6: Usage of fundamental deviation [Boundy]

ISO ()

Holes: A, B, C, CD, D, E, EF, F, FG, G, H, JS, J, K, M, N, P, R, S, T, U, V, X, Y, Z, ZA,ZB, ZC

Shafts: a, b, c, cd, d, e, ef, f, fg, g, h, js, j, k, m, n, p, r, s, t, u, v, x, y, z, za, zb, zc

(basic size), (fundamental deviation) (tolerance) designation

4.6 (clearance fit) (minimum clearance) c d c11 H11 H11-c11 H11-d11 11

4.7 4.8

4.3 (basic size), (fundamental deviation) (tolerance) 10mm H11-h11

(fundamental deviation)

(fundamentaldeviation)


7/17

4.3. 25

4.7: Fundamental deviation for holes [?]

4.8: Fundamental deviation for shafts [?]


8/17


(hole-basis system) (shaft-basissystem)

hole-basis 4.1 4.2

4.3 4.4 shaft-basis

hole-basis system

4.3.1 Coarse Tolerance (H11/c11 or C11/h11)

clearnace fit

4.3.2 Loose Running (H9/d10 or D10/h9)

(loose running fit) (idler gears and pulleys) , turbine

4.3.3 Easy Running (H9/e9 or E9/h9)

(easy running fit) loose running fit mainbearings, camshaft bearings, valve rocker shaft

4.3.4 Normal Running (H8/f7 or F8/h7)

,

4.3.5 Precision Running and Sliding (H7/g6 or G7/h6)

4.3.6 Average Location (H7/h6)


9/17

4.1-4.2: Hole-basis [Boundy]

27-28


10/17

4.3-4.4: Shaft-basis [Boundy]

29-30


11/17

4.3. 31

4.3.7 Light Push Fit (H7/k6 or K7/h6) transition fit

4.3.8 Heavy Push Fit (H7/n6 or N7/h6) transition fit (clearance)

4.3.9 Press Fit (H7/p6 or P7/h6) interfererence fit (ferrous)

4.3.10 Heavy Press Fit (H7/s6 or S7/h6) interference fit 10

bushes, sleeves, liners, seats.

4.3.11 4.1 4.4

8 mm designation H7-g6 4.1 0 +0.015

-0.014 -0.005 8+0.015

0

8

-0.005-0.014

8.0158.0

7.9957.986

4.3.12 4.9 (housing) (4) (capscrew) 6 4.5

(1)

running sliding average location (H7/h6) light push


12/17


4.9:


13/17

4.3. 33

fit heavy push fit, press fit, heavy press fit heavy push fit push fit press

fit , , ( )

heavy push fit press fit H7/p6 (2) running fit

normal running , ,

(3) (1) coarse

tolerance 30 0.5 28 0.5 (4)

running fit

average location light push fit light push fit

average location H7/h6 (5) (4) (0.5-1 mm ) clearance hole

(6) average location, light push fit, heavy push fit average location , heavy press fit

light push fit

4.3.13

general tolerances

4.6 4.7


14/17


4.5: (mm)

Feature Designation upper limit lower limit(1) Housing 20 H7 20.021 20.000(1) Bush 20 p6 20.035 20.022(2) Bush 12 H8 12.027 12.000(2) Shaft 12 f7 11.984 11.966(3) Housing 28 - 30.5 29.5(3) Bush 28 - 28.5 27.5(4) Cover 60 H7 60.030 60.000(4) Housing 60 h6 60.000 59.981(5) Cover 8 - 8.5 9.5

(5) Screw M8 - - -(6) Gear 16 H7 16.018 16.000(6) Shaft 16 k6 16.012 16.001

4.6: [Boundy]


15/17

4.3. 35

4.7: [Boundy]

4.8: [Boundy]

4.8 4.10

Method 1: Limits of size 4.11

Method 2: Bilateral tolerances 4.12

Method 3: Unilateral tolerances

4.13


16/17


4.10: [Boundy]

4.11: [Boundy]

4.12: [Boundy]


17/17

4.3. 37

4.13: [Boundy]

Fits and Tolerances

Documents

Transcript of Fits and Tolerances