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  3. ISO 4759-3 - Tolerances for fasteners -- Part 3: Plain washers for bolts, screws and nuts -- Product grades A and C

ISO 4759-3 - Tolerances for fasteners -- Part 3: Plain washers for bolts, screws and nuts -- Product grades A and C

Tolerance fasteners - Flat washers for screws and nuts - Product grades A and C


element Tolerance
production class
A A A C C
3.1 Inside diameter (The split) h mm d1 tolerance class h1 minimum h mm d1tolerance class
h≤4 H13 0,5h h≤4 H14
h>4 H14 0,3h h>4 H15
Fillets and chamfers are not fixed but are made. h1, fillets and chamfers are not fixed, but are made.
Legend
1 Fillet2 chamfer		 h1 is the part of the hole, which is specified for the tolerance range d1.

element Tolerance
production class
A A C
3.2 The outer diameter (The split) h mm d2 tolerance class d2 tolerance class
h≤4 h14 h16
h>4 h15
h2fillets and chamfers are not fixed, but are made
Legend
1 fillet two chamfers		 h2 is that part of the outer contour of which is within the tolerance specified for d.

element tolerances
production class
A C
3.3 thickness h h h h
mm tolerances mm mm tolerances mm
h≤0,5 卤0,05 h≤0,5 卤0,1
0,5<h≤1 卤0,1 0,5<h≤1 卤0,2
1<h≤2,5 卤0,2 1<h≤2,5 卤0,3
2,5<h≤4 卤0,3 2,5<h≤4 卤0,6
4<h≤6 卤0,6 4<h≤6 卤1
6<h≤10 卤1 6<h≤10 卤1,2
10<h≤20 卤1,2 10<h≤20 卤1,6
3.4 chamfer α= 30掳 a啪 45掳
emin = 0,25h
emax = 0,5h

Element Tolerances
Production class
3.5 Tolerance shape and position A C
3.5.1 The variability of thickness Δh is one of the reference surfaces h mm Δh mm
h≤0,5 0,025 not required
0,5<h≤1 0,05
1<h≤2,5 0,1
2,5<h≤4 0,15
4<h≤6 0,2
6<h≤10 0,3
Note
Requirements Δh Valid for h = 0.1 x distance (d2-d1) as the inner diameter and the outer diameter thn. Only 60% of the difference (d1-d2)		 10<h≤20 0,4

Element Tolerance level
3.5.2 Alignment production class
A A C C
d2 mm t1 d2 mm t1
d2≤50 2 IT12 d2≤50 2IT15
Note. D2 is crucial base for t1 d2>50 2IT13 d2>50 2IT16
3.5.3 flatness h t2 a
mm t2 a mm
Especially stainless steel
h≤0,5 0,1 not required
0,5<h≤1 0,15
1<h≤2,5 0,2
2,5<h≤4 0,3
4<h≤6 0,4
6<h≤10 0,6
10<h≤20 1
stainless steel
h≤0,5 0,15
0,5<h≤1 0,22
1<h≤2,5 0,3
2,5<h≤4 0,45
4<h≤6 0,6
Note Tolerance t2 is always independent of the tolerance of thickness h. 6<h≤10 0,9
a Flatness is measured after removing the burrs 10<h≤20 1,5

The numerical values of basic tolerances for individual IT tolerance grades in millimeters


nominal dimensions Tolerance grades
mm IT12 IT13 IT15 IT16
nad do Tolerance
3 0,1 0,14 0,4 0,6
3 6 0,12 0,18 0,48 0,75
6 10 0,15 0,22 0,58 0,9
10 18 0,18 0,27 0,7 1,1
18 30 0,21 0,33 0,84 1,3
30 50 0,25 0,39 1 1,6
50 80 0,3 0,46 1,2 1,9
80 120 0,35 0,54 1,4 2,2
120 180 0,4 0,63 1,6 2,5
180 250 0,46 0,72 1,85 2,9

Tolerances holes


Nominal dimensions mm) tolerances
nad do H13 H14 H15
3 +0,14
0		 +0,25
0		 +0,4
0
3 6 +0,18
0		 +0,3
0		 +0,48
0
6 10 +0,22
0		 +0,36
0		 +0,58
0
10 18 +0,27
0		 +0,43
0		 +0,7
0
18 30 +0,33
0		 +0,52
0		 +0,84
0
30 50 +0,39
0		 +0,62
0		 +1
0
50 80 +0,46
0		 +0,74
0		 +1,2
0
80 120 +0,54
0		 +0,87
0		 +1,4
0
120 180 +0,63
0		 +1
0		 +1,6
0
180 250 +0,72
0		 +1,15
0		 +1,85
0

Tolerances Shaft


nominal dimensions
mm)		 tolerances
nad do h13 h14 h15
3 0
-025		 0
-0,4		 0
-0,6
3 6 0
-0,3		 0
-0,48		 0
-0,75
6 10 0
-0,36		 0
-0,58		 0
-0,9
10 18 0
-0,43		 0
-0,7		 0
-1,1
18 30 0
-0,52		 0
-0,84		 0
-1,3
30 50 0
-0,62		 0
-1		 0
-1,6
50 80 0
-0,74		 0
-1,2		 0
-1,9
80 120 0
-0,87		 0
-1,4		 0
-2,2
120 180 0
-1		 0
-1,6		 0
-2,5
180 250 0
-1,15		 0
-1,85		 0
-2,9