jcb JS300 Service Manual page 31

Zinc Plated Fasteners and Dacromet Fasteners
Introduction
Some external fasteners
manufactured using an improved type of corrosion
resistant finish. This type of finish is called Dacromet and
replaces the original Zinc and Yellow Plating used on
earlier machines.
The two types of fasteners can be readily identified by
colour and part number suffix.
( T
1-26).
Table 1. Fastener Types
Fastener Colour
Type
Zinc and Golden finish
Yellow
Dacromet Mottled silver finish 'D' (e.g. 1315/3712D)
Note: As the Dacromet fasteners have a lower torque
setting than the Zinc and Yellow fasteners, the torque
figures used must be relevant to the type of fastener.
Note: A Dacromet bolt should not be used in conjunction
with a Zinc or Yellow plated nut, as this could change the
torque characteristics of the torque setting further. For the
same reason, a Dacromet nut should not be used with a
Zinc or Yellow plated bolt.
Note: All bolts used on JCB machines are high tensile and
must not be replaced by bolts of a lesser tensile
specification.
Note: Dacromet bolts, due to their high corrosion
resistance are used in areas where rust could occur.
Dacromet bolts are only used for external applications.
They are not used in applications such as gearbox or
engine joint seams or internal applications.
1-26
on JCB machines are
K Table 1. Fastener Types
Part No. Suffix
'Z' (e.g. 1315/3712Z)
1-07-00 Issue 01
Section 1 - General Information
Zinc Plated Fasteners and Dacromet Fasteners
T11-002
Bolts and Screws
Use the following torque setting tables only where no
torque setting is specified in the text.
Note: Dacromet fasteners are lubricated as part of the
plating process, do not lubricate.
Torque settings are given for the following conditions:
Condition 1
– Un-lubricated fasteners
– Zinc fasteners
– Yellow plated fasteners
Condition 2
– Zinc flake (Dacromet) fasteners
– Lubricated zinc and yellow plated fasteners
– Where there is a natural lubrication. For example,
cast iron components
Verbus Ripp Bolts
Torque settings for these bolts are determined by the
application. Refer to the relevant procedure for the
required settings.
Torque Settings
Fig 1.
1-26