Thread sizes???

Submitted: Tuesday, Apr 12, 2005 at 17:54
ThreadID: 22006 Views:6222 Replies:8 FollowUps:18
This Thread has been Archived
I'm just in the process of working out an order to place with VDO for some gauges and associated sender units. I know from bitter experience with my oil pressure sender unit, that Nissan engines do not have NPBT threads. I am going to order a coolant temp gauge and sender with 1/8" NPBT thread. I can also order a small brass adaptor with this thread on it's inside diameter and I have a choice of M14, M16 and M18 outside threads to choose from. I want to instal the sender at the top of the thermostat housing, near the position of OE sender unit. I have 2 choices: there is a hex bolt which is just filling a hole and there is also another brass fitting with a barb on it which points upwards at about 45 degrees and has a rubber stopper over it's end. It seems as though it was intended to have a hose going off to another part of the motor, but Mr Nissan decided that it wasn't needed on the Australian model.
Now, finally, to my question......how do I measure the size of the threads in the fitting/s when I remove them? I have a micrometer and can measure the diameter of the thread either on the outside of the thread or in the groove of the thread. I believe the M14 relates to 14mm diameter, but not sure where this measurement is taken from?
Any engineers out there who can enlighten me please?
Thanks in advance blokes
Cheers
Roachie
Back Expand Un-Read 0 Moderator

Sponsored Links