NORD-LOCK® STEEL CONSTRUCTION WASHERS

USER GUIDE

How to use our Nord-Lock steel construction washers.

Instructions

Use our joint guide to help you use Nord-Lock steel construction washers correctly.

Link to full version of Nord-Lock Steel Construction Washers User Manual

Through-holes

Through-holes require the use of two pairs of Nord-Lock SC-washers. One pair for securing the bolt and a second pair for securing the nut. Turn both fasteners in order to close the cams on both washer pairs before tightening to minimize settlements. Keep the bolt secure whilst tightening the nut.

Designs where Nord-Lock SC-washers are not recommended:

With plain washers
When mating surfaces are not locked in place
When mating surfaces are harder than the washers
With very soft mating surfaces — for example, wood and plastic
For applications with extreme settlements
When there is no clamping force in the joint

ASSEMBLY INSTRUCTIONS

To install Nord-Lock steel construction washers, follow these 4 simple steps:

1.

Place one pair of Nord-Lock washers underneath the head of the bolt and mount it in the through hole. Place the second pair of washers on the bolt and mount the nut.

2.

Turn both fasteners (bolt head/nut) in order to close the cams on both washers before tightening to minimize settlements.

3.

Keep the bolt/nut secured while tightening the other part (bolt/nut). For guidance on which torque to tighten with, check the Nord-Lock torque guidelines.

4.

Ready!

Torque Guidelines Steel Construction Washers, Table 1

Tightening torques to achieve the preloading force for bolting assemblies that originally corresponded to k-class K1 (usually System HV according to EN 14399-4 or EN 14399-8).

		Torque method
Bolt size	Product name	Tightening torque M_CM,SC [Nm]	Preloading force ¹⁾without retightening F_p,C,red* [kN] (90%)	Preloading force F_p,C* [kN]
M12	NL12SC	165	45	50
M16	NL16SC	400	90	100
M20	NL20SC	800	144	160
M22	NL22SC	1.100	171	190
M24	NL24SC	1.300	198	220
M27	NL27SC	1.900	261	290
M30	NL30SC	2.300	315	350
M36	NL36SC	4.050	459	510

1) Differentation between Fp,C,red* and Fp,C* is only relevant for bolted categories B and C

Torque Guidelines Steel Construction Washers, Table 2

Pre-tightening torque for the combined method to achieve the preloading force for bolting assemblies that originally corresponded to k-class K1 (usually System HV according to EN 14399-4 or EN 14399-8).

		Combined method ¹⁾
Bolt size	Product name	Tightening torque M_TM,SC [Nm]	Preloading force F_p,C [kN]
M12	NL12SC	120	59
M16	NL16SC	290	110
M20	NL20SC	510	172
M22	NL22SC	720	212
M24	NL24SC	880	247
M27	NL27SC	1.300	321
M30	NL30SC	1.700	393
M36	NL36SC	2.700	572

1) For additional rotation angles  EN 1090-2 Table 21 applies

Torque Guidelines Steel Construction Washers, Table 3

Additional rotation for the second step in the combined method (8.8 and 10.9 bolts).

Total nominal thickness "t" of parts to be connected (including all packs and washers) d = bolt diameter	Further rotation to be applied, during the second step of tightening
	Degress	Part turn
t > 2d	60	1/6
2d ≤ t < 6d	90	1/4
6d ≤ t ≤ 10d	120	1/3
10d < t	No recomendations

Tightening angles when using the combined method varies depending on the clamp length, (t), in relation to bolt diameter, (d).

Torque Guidelines Steel Construction Washers, Table 4

Additional rotation for the second step in the combined method (8.8 and 10.9 bolts).

Designation	Nominal diameter	Torque method
Designation	Nominal diameter	Tightening torque M_T,SC,sec [Nm]
NL12SC	M12	80
NL16SC	M16	200
NL20SC	M20	360
NL22SC	M22	520
NL24SC	M24	640
NL27SC	M27	1.000
NL30SC	M30	1.320
NL36SC	M36	2.240