John King Chains

18.5 Forged Fork link chain

In following conveyor chain convention the KING range of forged fork link chain offers a range of materials and heat treatments dependent on the demand of the application. The following options are available.
TN Standard series low alloy steel case carborised. General duty with good abrasion resistance.
CN High Alloy steel case carborised. Enhanced performance in corrosive and abrasive environments.
C Carbon steel through hardened. Increased tensile strength over TN/CN with average abrasion resistance.
CD High Alloy direct hardening steel. Through hardened for high strength and toughness, well suited for long conveyors with high chain pull.
SS Martensitic 420. Through hardened. High strength with good corrosion and abrasion resistance.
SS Austenitic 304/316. Optimum corrosion resistance with poor abrasion resistance.

Table 18.5.1 Forged Fork link chains

JK Code

Material

Rm
(Tensile strength)
[N/mm²]

Re
(Yield strength)
[N/mm²]

A5 [%]

H/T

[HRC]
hardness
(depth [mm])

Corrosion resistance

Wear resistance

Elements [%]

ISO

Equiv.

C

Si

Mn

Cr

Mo

Other

CD

42CrMo4

4140

1100-1300

900

11

T

32-36

Good

Good

0.38-0.45

<0.4

0.6-
0.9

0.9-1.2

0.15-0.3

-

TN

20CrMnTi

as MN

1080

835

10

C

57-61/
(0.6-0.8)

Average

Very good

0.17-0.23

0.17-0.37

0.8-1.1

1.0-1.3

-

Ti 0.04-0.1

MN

18MnCrB5

1.7183,
1.7160

1000-1300

700

8

C

57-61/
(0.6-0.8)

Average

Very good

0.2

0.25

1.15

-

-

B and Pb

CN

18NiCrMo5

4317,
18NCD5

930-1230

735

9

C

57-61/
(0.6-0.8)

Good

Very good

0.15-0.21

0.15-0.4

1.15

0.7-1.0

0.15-0.25

Ni 1.2-1.5

SS

304

1.4301,S3

520

210

45

-

(15)

Very good

Poor

<0.08

<1.0

<2.0

17.5-20.0

-

Ni 8.0-11.0

 

316

1.4401, S4

520

210

40

-

(15)

Excellent

Poor

<0.08

0.75

<2.0

16.0-18.0

2.0-3.0

Ni 10.0-14.0

 

420

1.4021, S5

1600

1400

10

T

46-48

Very good

Good

0.15-0.36

1.0

12.0-14.0

-

Ni 1.0

C

C45

1045

850

500

14

T

52-55

Average

Good

0.42-0.50

1.0

0.45-0.85

0.40-0.45

0.10-0.15

Ni 0.40-0.45

H/T code
T – Thru-hardened
C – Case Hardened
I – Induction hardened
A – Annealed