Post by doristhechicken on Jul 13, 2018 14:21:24 GMT 12
Have a couple of questions about inspection of critical fastening requirements. Everything is going to be loctited of course, but meeting inspection requirements in some situations is not easy.
1. Fasteners on pre-assembled components - do these need to be removed and re-attached with visible anti-vibration measures? I would assume not.
2. What if above bolts need to be removed and replaced in a way that would be obvious?
3. What if not possible to meet requirements? eg blind tapped recessed socket head bolt? (ie can't see a lock washer)
4. Are other systems such as safety wire, nord-lock washers acceptable?
Relevant section below followed by some questions:
18.2 General fastener requirements
18.2.1
A fastener used in a safety-related application within a low
volume vehicle must:
(a) be of an appropriate size and grade for the application; and
(b) be secured with a ‘nyloc’ nut, spring washer, split-pin, or
other vibration-proof locking device; and
(c) be in good condition.
18.2.2
A fastener used in a safety-related application within a low
volume vehicle must not:
(a) have any head markings incorporated by the fastener
manufacture removed; or
(b) in the case of a stainless steel fastener, be electroplated.
18.2.3
‘Loctite’ or other thread
adhesives are not an
approved vibration-proof
locking device for the
purpose of LVV
certification, as such a
system puts the LVV
Certifier in a position
where he would be
‘approving’ something
he can’t see.
Normal single-grip spring
washers should not be
used against aluminium
surfaces as they will
gouge the aluminium –
‘nylocs’ or multi-grip
washers should be used
instead.
The threaded section of a fastener used in a safety-related
application within a low volume vehicle must protrude through the
outer end of the nut to which it attaches by not less than two full
threads.
1. Fasteners on pre-assembled components - do these need to be removed and re-attached with visible anti-vibration measures? I would assume not.
2. What if above bolts need to be removed and replaced in a way that would be obvious?
3. What if not possible to meet requirements? eg blind tapped recessed socket head bolt? (ie can't see a lock washer)
4. Are other systems such as safety wire, nord-lock washers acceptable?
Relevant section below followed by some questions:
18.2 General fastener requirements
18.2.1
A fastener used in a safety-related application within a low
volume vehicle must:
(a) be of an appropriate size and grade for the application; and
(b) be secured with a ‘nyloc’ nut, spring washer, split-pin, or
other vibration-proof locking device; and
(c) be in good condition.
18.2.2
A fastener used in a safety-related application within a low
volume vehicle must not:
(a) have any head markings incorporated by the fastener
manufacture removed; or
(b) in the case of a stainless steel fastener, be electroplated.
18.2.3
‘Loctite’ or other thread
adhesives are not an
approved vibration-proof
locking device for the
purpose of LVV
certification, as such a
system puts the LVV
Certifier in a position
where he would be
‘approving’ something
he can’t see.
Normal single-grip spring
washers should not be
used against aluminium
surfaces as they will
gouge the aluminium –
‘nylocs’ or multi-grip
washers should be used
instead.
The threaded section of a fastener used in a safety-related
application within a low volume vehicle must protrude through the
outer end of the nut to which it attaches by not less than two full
threads.