Originally Posted by ZeeOSix
Originally Posted by oldhp
The threads are different; The correct threads are 22X1.5-6-H MM. The -6-H means the threads have a different pitch. Example would be metric nut on a standard thread bolt, it will kinda tighten but not right. You must use the 22 X 1.5-6-H threaded oil filters.
The FL-820-S crosses to a WIX 1372 which is 22 X 1.5 threads, won't work. The correct WIX filter is 57899 which is the correct 22 X 1.5-6-H threads.
This should clear up any confusion on the threads. The "6H" is nothing but the "thread tolerance class", which is a measure of how loose or tight the threads fit together. It does not mean the threads are a different pitch.
There is nothing special about a "6H" thread tolerance.
http://www.engineeringessentials.com/ege/fast/fast_page7.htm
Tolerance Class: It describes the looseness or tightness of fit between the internal and external threads. Two classes of metric thread fits are generally used.
6H/6g = General purpose. A tolerance class of 6H/6g is assumed if it is not specified.
6H/5g6g = Closer fit.
Tolerance Grade: (Number) Smaller numbers indicate a tighter fit.
Tolerance Position: (Letter) Specifies the amount of allowance.
Upper case letters = internal threads
Lower case letters = external threads
From this link - metric thread spec start on page 6:
http://homepages.cae.wisc.edu/~me231/online_notes/dimensoning/fastener_handout.pdf
Metric thread fits:
A fit between metric threads is indicated by internal thread class fit followed by external thread tolerance class separated by a slash; e.g., M10 x 1.5-6H/6g. The class fit is
specified by tolerance grade (numeral) and by tolerance position (letter).
General purpose fit
6g (external)
6H (internal)
Close fit
5g6g (external) 6H (internal)
If thread fit designation (e.g., "-6g") is omitted
(e.g., M10 x 1.5), it specifies a "medium" fit, which is 6H/6g. The 6H/6g fit is the standard ISO tolerance class for general use.
English unit internal and external thread class fit 2B/2A is essentially equivalent to ISO thread class fit 6H/6g. English unit class fit 3B/3A is approximately equivalent to ISO class fit 4H5H/4h6h.
So I realize I'm necrothreading 5 years back but THANK YOU! for stating clearly what I was screaming in my head while reading the entire thread.
Any machinist will tell you the variation argued about here was just thread tolerance....which for your average guy is basically irrelevant....and save for maybe jet engines or aerospace or maybe professional drag racing (read: TONS of vibration) I simply can NOT fathom an oil filter application where thread tolerance would matter at all.
They all get basically hand tightened and bump up against a relatively thick rubber gasket.
I think I saw the same bad info about -6H in Amazon reviews, so it's good to clear up internet lore. An M22x1.5 is an M22x1.5
