Plain Washers 7 KSB1326

KS B 1326KSKSKSKSSKSKSKS KSKSKS SKSKS KSKS SKS KS

Plain washers

KS B 1326 : 1980(Confirmation in 2005)

Industrial Standards Deliberate Council. DeliberationAmendment on December 24, 1980

Published by Korean Standards Association

2012-02-20, 대진볼트공업(주)에 라이센스를 부여하며 불법 복사 및 무단 배포를 금합니다.

List

Name Place of Work Position (Chairman)

(Committee)

Legislator: Administrator Agency for Technology and Standards Establishment: October 20, 1971 Revision: December 24, 1980 Confirmation: December28,2005 Agency for Technology and Standards Notification No.2005-1008 Draft cooperator: Machine Basis Element 2nd Part of Industrial standards deliberate council Deliberate council: Machine Basis Element 2nd Part of Industrial standards deliberate council (Chairman: YOU Bong-Hwan)

Call Agency for Technology and Standards Agency for construction service department (02- 509- 7402) for any comments or inquiries regarding these standards. Furthermore, under the provision of the industry standard law article number 7 the Korean Industrial Standard is checked, amendment or abolished by the deliberate council of general industry every 5 years.


1

Korean Industrial Standard KS B 1326 : 1980

Plain washers

1 Scope

This standard text defines circular plain washers (1) (hereinafter referred to as circular washers) made of steel,

stainless steel and brass or squared plain washers (1) (hereinafter referred to as angular washers) used for normal

bolts, nuts and small threads. However, washers for wooden construction use are excluded.

Note (1) The term ‘washers’ refers to circular washers and angular washers both.

2 Normative references

Respective standards of this standard text are as follows.

KS B 0161 Definition of surface roughness and display

KS B 1002 Hexagon bolts

KS B 1004 Square head bolts

KS B 1012 Hexagon nuts

KS B 1013 Square head nuts

KS B 1021 Slotted head screws

KS B 1023 Cross-recessed head machine screws

KS D 2301 Copper billets and cakes

KS D 3501 Hot-rolled mild steel plates and strip

KS D 3503 Rolled steel strip for normal structural use

KS D 3512 Cold rolled stainless steel plates and strip

KS D 3752 Carbon steel for machine structural use

KS D 5505 Brass sheets

KS D 5513 Brass tapes

KS D 6701 Aluminium and aluminium alloy sheets and plates, strips and coiled sheets

3 Types

As shown in Table 1, the type of circular washers is classified by the size and surface condition, while that of angular

washers is classified by the size.


KS B 1326 : 1980

2

Table 1

Washers Types Application screw parts

KS B 1021: pan, round, flat, round-flat headed small threads

KS B 1023: pan, round headed small threads Small circle

KS B 1002, KS B 1012: small hexagon bolts, small hexagon nuts

KS B 1023: small threads for truss or binding Glossy circle KS B 1002, KS B 1012: hexagon bolts, hexagon nuts of the high or

medium finishing quality

Circular washers

Normal circle KS B 1002, KS B 1012: hexagon bolts, hexagon nuts of the normal finishing quality

Small square Angular washers

Large square

KS B 1002, KS B 1012, KS B 1004, KS B1013: hexagon bolts & nuts, square bolts & nuts of the normal finishing quality. Also big square bolts & nuts are used for wooden joint

4 Hardness

4.1 Hardness of steel washers

Hardness of steel washers is classified into three categories as shown in Table 2, and its applications are suggested

in Table 3.

Table 2

Hardness (3)

Vickers hardness Rockwell hardness Classification of

hardness (2) Min Max Min Max

10 H HV 100 - HRB 57 -

14 H HV 140 HV 220 HRB 75 HRB 95

22 H HV 220 HV 300 HRB 95 HRC 29

Note (2) Symbol for hardness classification is expressed as 1/10 of figures of Vickers

hardness (min) plus H representing hardness.

(3) Hardness can be either Vickers hardness or Rockwell hardness.

Table 3

Reference Classification of hardness Classification of washers applied

Small threads applied (4)

10 H Angular washers 4.6, 4.8, 4T

14 H 4.6, 4.8, 5.6, 5.8, 6.6, 6.8, 4T, 5T, 6T

22 H

Circular washers

8.8, 10.9, 7T

Note (4) Strength classification of bolts and small threads is based on KS B 0233. Washers for the

strength classification 12.9 are not regulated. However, if such a regulation is required, the

hardness equivalent to plain washers defined by KS B 1010 may apply.


KS B 1326 : 1980

3

4.2 Hardness of non-steel washers

Hardness of non-steel washers (the small circle & the glossy circle of stainless steel or brass) is suggested in Table 4.

Table 4

Types Material classification Vickers hardness

Stainless steel Above HV 120 Small circle or glossy circle

Brass Above HV 65

5 Shapes and sizes

The shapes and sizes of washers are as follows.

Table 5

Classification Shapes and sizes Range of diameter (mm)

Small circle Appendix Table 1 1 – 39

Glossy circle Appendix Table 2 2 – 80

Normal circle Appendix Table 3 6 – 150

Small square 6 – 27

Large square Appendix Table 4

6 – 52

6 Bending or offcenter of holes

The bending of washers and the offcenter of holes are as follows.

(1) Bending Bending of circular washers is based on Appendix Table 1 – 3.

(2) Offcenter of holes Offcenter of holes of circular washers or angular washers is suggested in Appendix Table 1 -4.

7 Appearance

With the surface roughness being in accordance with the rules of Appendix Table 1 -4, the outside appearances of

washers must not have quenching rupture, cracks, harmful marks, rust, steel residues and other defects.

8 Materials

Washers materials are principally based on Table 6.


KS B 1326 : 1980

4

Table 6

Materials Classification

Types of materials Application standard

KS D 3503

KS D 3512 Steel

KS D 3752

KS D 3698

KS D 3700 Stainless steel

KS D 3705

KS D 5505: type 1, type 2, A · B, type 3

Small circle, glossy circle

Brass KS D 5513: type 1, type 2, A · B, type 3

KS D 3503

KS D 3501 Normal circle Small square

Large square Steel

KS D 3752

9 Surface treatment

Surface treatment is not done on washers. Special plating or other surface treatment can be done, but subject to an

orderer’s instruction.

10 Test & measurement method

10.1 Hardness test

Washers hardness is tested on the plain areas of washers in accordance with the rules of KS B 0811 or KS B 0806.

10.2 Bending measurement method

For the bending measurement, a washer is placed on a surface plate. The height (H) in Figure 1 is measured by

using a height gage or other measurement equipment. Such a height (H) is subtracted from the measured width of

the washer (T). The value (H-T) is the bending of the washer (C).

Figure 1

Also, it must be stably placed on the surface plate. H is the maximum height and T is the thickness around the

highest location.

Remark 1 The surface place used must meet the specifications defined by KS B 5254 or something with the

similar level of precision.

2 The height gage used must meet the specification of KS B 5233.

Surface plate

Washer


KS B 1326 : 1980

5

10.3 Measurement method for the offcenter of holes

For the measurement of the offcenter of holes, vernier calipers or other measurement equipments are used. As

shown in Figure 2, a, b is measured and the subtraction (a-b) equals the offcenter of holes. a and b for circular

washers or angular washers are the maximum or the minimum values of eccentricity.

Remark Vernier calipers used is in accordance with the rules of KS B 5203.

Figure 2

11 Inspection

Inspections for washers are as follows. However, sampling for the lot inspection is subject to the agreement between

parties.

(1) Hardness inspection When hardness inspection is done in accordance with the rules of 9.1, the result must

meet the regulations of 3. Either Vickers hardness or Rockwell hardness can be chosen for the hardness test,

unless the agreement between parties specifies others.

(2) Inspection for shapes and sizes Based on the rules of 4., inspection for shapes and sizes is done through

the limit gauge, direct measurement and etc.

(3) Bending inspection When being done based on the rules of 9.2, bending inspection must meet the regulations

of 5.(1)

(4) Inspection for the offcenter of holes When the inspection is done in accordance with the rules of 9.3, the

result must meet the regulations of 5.(2).

(5) Inspection for appearances The appearances of washers are done through inspector’s eyes according to

the rules of 6. The surface roughness is tested by using the surface roughness measuring instrument, the surface

roughness standard machine or other appropriate methods.

Remark The surface roughness standard machine used meets (or exceeds) the precision level defined by KS B 0507 with the precision level of the surface roughness measuring instrument meeting (or exceeding) that

of KS B 0501.

12 Naming products

How to name washers depends on standard number or standard name, type, sizes, diameter, hardness

classification, materials and instructions (5). For steel washers, materials are excluded from the names, while

hardness classification is excluded from the names of non-steel washers.

Note (5) Instructions display types of surface treatment, chamfering and thickness, if necessary. If the major

diameter and thickness (t) are instructed, the value is expressed as diameter x the major diameter x t.


KS B 1326 : 1980

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Example KS B 1326 Small circle 6 Nickel plating

KS B 1326 Glossy circle 12 -22H Major diameter

Plain washer Large square 16X6 -10H Chamfering

Plain washer Normal circle 10X28X2.5 -14H

∥ ∥ ∥ ∥ ∥ ∥ (Standard number (Type) (Diameter x (Hardness (Materials) (Instructions)

or standard name) major diameter x classification)

width)

13 Display

The packaging must contain the following contents.

(1) Name

(2) Type

(3) Diameter

(4) Hardness classification (for steel washers)

(5) Materials (6)

(6) Instructions

(7) Quantity

(8) Name of manufacturer or symbol

Note (6) Material displays are done for washers of stainless steel or brass. In principal, washers of steel are not

required to display materials used. General names can be used for displaying materials.


KS B 1326 : 1980

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Appendix Table 1 Small circle

unit : mm

d D a - b t c diameter standard

sizes limits of

sizes standard

sizes limits of

sizes maximum standard sizes

limits of sizes maximum

1 1.1 2.5 0.3 1.2 1.3 2.8 0.3

(1.4) 1.5 3

0 -0.25 0.2

0.3 1.6 1.7 3.8 0.3

*(1.7) 1.8 3.8 0.3 2 2.2 4.3 0.3

±0.04

(2.2) 2.4 4.6 0.5 *(2.3) 2.5 4.6 0.5 2.5 2.7 5 0.5

*(2.6) 2.8

+0.15 0

5 0.5 3 3.2 6

0 -0.3 0.24

0.5 (3.5) 3.7 7 0.5

±0.05

0.05

4 4.3 8 0.8 (4.5) 4.8 9 0.8 5(7) 5.3

+0.2 0

10

0 -0.35 0.3

1

±0.1 0.1

6 6.4 11.5 1.6 8 8.4

+0.25 0 15.5 1.6

±0.15

10 10.5 18

0 -0.4 0.36

2 ±0.2 12 13 21 2.5

(14) 15 24 2.5 ±0.25

0.2

16 17

+0.3 0

28 3 (18) 19 30

0 -0.5 0.42

3 20 21 34 3

(22) 23 37 3

±0.3

24 25 39 4 (27) 28

+0.35 0

44 4 30 31 50

0 -0.6 0.5

4

±0.4

0.3

(33) 34 56 5 36 37 60 5

±0.5

(39) 40

+0.4 0

66

0 -0.8 0.6

6 ±0.6

0.4

Offcenter of holes (a - b) bending (c)


KS B 1326 : 1980

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Note (7) Small circle with the diameter of 5 is the same as glossy circle.

Remark 1 Diameters in the above table correspond to those of metric screw threads.

2 The diameters with mark ( ) are not used if possible.

The diameters with * mark are based on KS B 0201, which are to be abolished. Therefore, it is

recommended that such diameters not to be used for new machines.

3 Standard sizes of the inner diameter (d) correspond to the diameter of bolt holes (class 1) of KS B 1007.

4 Surface roughness in the above figure is in accordance with KS B 0161.

5 The inner diameter (d) and the major diameter (D) may include taper due to blanking. However, taper (t)

must be less than 18 % of the standard size of the thickness.

6 The inner diameter (d) for the diameter of 1.6, 2.2 or 2.5 may be the same as that for the diameter of 1.7,

2.3 or 2.6 in line with an agreement between parties.

7 Standard sizes of the sheet thickness (t) for the diameter of 16 – 22 may be 3.2 mm in line with an

agreement between parties.

8 If bigger washers than the above figures are required, the glossy circle figures of Appendix Table

2 may be referred to.

Reference 1 Standard sizes of d, D or t for the diameter of above 8 correspond to fine series or small figures of

ISO R 887.

2 Offcenter of holes (a-b) follows IT 12 x 2 based on the major diameter (D), and IT 12 is in accordance

with IT basic tolerances (class 12) of KS B 0401.

3 Bending figures (c) are based on grade A of Flatness defined in ISO 4759/Ⅲ.

Taper due to blanking

0.09t below 0.09t below


KS B 1326 : 1980

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Appendix Table 2 Glossy Circle

unit : mm

d D a - b t c Diameter Standard

sizes Limits of

sizes Standard

sizes Limits of

sizes Maximum Standard sizes

Limits of sizes Maximum

2 2.2 5 -0 -0.3 0.24 0.3 ±0.04

(2.2) 2.4 6.5 0.5 *(2.3) 2.5 6.5 0.5 2.5 2.7 6.5 0.5

*(2.6) 2.8

+0.15 0

6.5 0.5 3 3.2 7 0.5

(3.5) 3.7 9 0.5

±0.05 0.05

4 4.3 9 0.8 (4.5) 4.8 10 0.8 5 (7) 5.3

+0.2 0

10

0 -0.35 0.3

1 ±0.1 0.1

6 6.4 12.5 1.6 8 8.4

+0.25 0 17

0 -0.4 0.36

1.6 ±0.15

10 10.5 21 2 ±0.2 12 13 24 2.5

(14) 15 28 2.5 ±0.25

0.2

16 17

+0.3 0

30

0 -0.5 0.42

3 (18) 19 34 3 20 21 37 3

(22) 23 39 3

±0.3

24 25 44 4 (27) 28

+0.35 0

50

0 -0.6 0.5

4 30 31 56 4

±0.4

0.3

(33) 34 60 5 36 37 66 5

±0.5

(39) 40 72 6 ±0.6 0.4

42 43 78

0 -0.8 0.6

7 (45) 46 85 7 48 50

+0.4 0

92 8 (52) 54 98 8 56 58 105 9

(60) 62 110 9 64 66 115 9

±0.7

(68) 70 120

0 -1 0.7

10 72 74 125 10

(76) 78

+0.5 0

135 10

0.6

80 82 +0.55 0 140

0 -1.2 0.8

12

±1

1

Offcenter of holes (a - b) Bending (c)


KS B 1326 : 1980

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Note (7) Small circle with the diameter of 5 is the same as glossy circle.



The diameters with * mark are based on KS B 0201, which are to be abolished. Therefore, it is

recommended that such diameters not to be used for new machines.





6 The inner diameter (d) for the diameter of 2.2 or 2.5 may be the same as that for the diameter of 2.3 or

2.6 in line with an agreement between parties.

7 Standard sizes of the sheet thickness (t) for the diameter of 16 – 22 may be 3.2 mm in line with an

agreement between parties.

8 Chamfering for the outer circle can be instructed if necessary. In this case, the size of chamfering

(e) is as follows if specified otherwise.

Reference 1 If washers with the large major diameter are needed, D on top of step 1 -3 or its respective t can be

used.

2 Standard sizes of d, D or t for the diameter of above 8 correspond to fine series or normal figures of

ISO R 887.

3 Offcenter of holes (a-b) follows IT 12 x 2 based on the major diameter (D), and IT 12 is in accordance

with IT basic tolerances (class 12) of KS B 0401.

4 Bending figures (c) are based on grade A of Flatness defined in ISO 4759/Ⅲ.

e minimum value=( standard value of t ) x 0.25e maximum value=( standard value of t) x 0.5About 45°

0.09t below


0.09t below


KS B 1326 : 1980

11

Appendix Table 3 Normal Circle

unit : mm

d D a - b t c Diameter Standard

sizes Limits of

sizes Standard

sizes Limits of


Limits of sizes Maximum

6 6.6 1.25 1.6 8 9

+0.6 0 17

0 -0.7 0.86

1.6 ±0.2

10 11 21 2 ±0.25 12 14 24 2.3 ±0.3

0.4

(14) 16 28 3.2 16 18

+0.7 0

30

0 -0.8 1.04

3.2 (18) 20 34 3.2 20 22 37 3.2

(22) 24 39 3.2

±0.4 0.6

24 26 44 4.5 (27) 30

+0.8 0

50

0 -1 1.24

4.5 30 33 56 4.5

±0.5

(33) 36 60 6 36 39 66 6

(39) 42 72 6

0.8

42 45 78

0 -1.2 1.48

7 (45) 48

+1 0

85 7 48 52 92 8

(52) 56 98 8

±0.7

56 62 105 9 (60) 66 110 9 64 70 115 9

(68) 74 120

0 -1.4 1.74

10

1.2

72 78

+1.2 0

125 10 (76) 82 135 10 80 86 140 12

(85) 91 145 12 90 96 160 12

(95) 101 165 12

±1

100 107 175 14 (105) 112 180

0 -1.6 2

14 110 117

+1.4 0

185 14 (115) 122 200 14 (120) 127 210 16 125 132 220 16

(130) 137 230 16

±1.4

140 147 24 18 (150) 158

+1.6 0

250

0 -1.8 2.3

18 ±1.6

2

Offcenter of holes (a - b) Bending (c)


KS B 1326 : 1980

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Reference 1 If washers with the large major diameter are needed, D on top of step 1 -3 or its respective t can be

used.

2 Standard sizes of d, D or t for the diameter of above 8 correspond to medium series or normal figures

of ISO R 887.

3 Offcenter of holes figures (a-b) follows IT 14 x 2 based on the major diameter (D), and IT 14 is in

accordance with IT basic tolerances (class 14) of KS B 0401.

4 Bending figures (c) are two times those of glossy circle.

0.09t below


0.09t below


KS B 1326 : 1980

13

Appendix Table 4 Small square or large square

unit : mm

d D a - b t D a - b t Diameter standard

sizes Standard

sizes Limits

of sizes Standard

sizes Limits of

sizes Standard

sizes Limits of


Limits of sizes Maximum Standard

sizesLimits

of sizes

6 6.6 17 0 -1.1 0.86 1.2 20 2.3

8 9

+0.6 0 23 1.6 26

0 -1.3 1.04

2.3 10 11 28

0 -1.3 1.04 1.6

±0.2

32 2.3

±0.3

12 14 35 2.3 ±0.3 40 3.2 (14) 16 40 3.2 44

0 -1.6 1.24

3.2 ±0.4

16 18

+0.7 0

45

0 -1.6 1.24

3.2 ±0.4 52 4.5 (18) 20 52 4.5 55 4.5 20 22 56 4.5 62 6

(22) 24 64 4.5 ±0.5

68 6 24 26 68 6 72 6

(27) 30

+0.8 0

73

0 -1.9 1.48

6 ±0.7 80

0 -1.9 1.48

6 30 33 - - 90 6

(33) 36 - - 100 8 36 39 - - 110 8

(39) 42

+1 0

- - 115 8

±0.5

±0.7

42 45 - - 120

0 -2.2 1.74

8 (45) 48

+1.5 0 - - 130 9

48 52 - - 140 12 (52) 56

+2 0 -

- -

-

-

150

0 -2.5 2

12

±1

Remark 1 Diameters in the above table correspond to those of metric screw threads. 2 The diameters with mark ( ) are not used if possible. 3 Standard sizes of the inner diameter (d) correspond to the diameter of bolt holes (class 2) of KS B 1007. 4 Surface roughness in the above figure is in accordance with KS B 0161. 5 The inner diameter (d) and the major diameter (D) may include taper due to blanking. However, taper (t)

must be less than 18 % of the standard size of the thickness (refer to the below figure).

6 If thick washers are required, t on top of step 1 may be used in line with an agreement between parties. 7 It is recommended that large squares to be used for wooden joint.

Reference Offcenter of holes (a-b) follows IT 14 x 2 based on the width (D), and IT 14 is in accordance with IT basic tolerances (class 14) of KS B 0401.

Offcenter of holes (a - b)

0.09t below


0.09t below


KS B 1326 : 1980

14

KS B 1326 : 1980 (Confirmation in 2005)

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Plain washers

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Plain Washers 7 KSB1326