Flat bottom tank rubber - normally fitted to the bottom of oil tanks - or occasionally Manx bolthru tanks. The same as petrol tank rubber Item - 0129, but with a fractionally smaller Internal diameter, more suited to 5/16" bolts. See listing for more detail.
Price is per each
Similar in appearance to the petrol tank rubber doughnuts (Item 0129), these oil tank rubbers have slightly different inner diameters - these being closer to 5/16" diameter, and were normally fitted to the bottom of oil tanks where a 5/16" shouldered bolt is used (while our petrol tank version of the same rubber - Item 0129 is more suited to the normal 3/8" diameter shouldered petrol bolt.
These were also used on Manx petrol tanks and oil tanks using 5/16" thru rods - and like Item 0129, they fit snugly in the dished washers we also sell in the same section.
Note: the difference between these and our Item 0129 is actually quite minimal . . . but we ended up making both types. If one is out of stock, the other can also be interchanged with no issue.
Just like Item 0129, these are manufactured for us by a specialist rubber manufacturer and are patterned on original Norton items from high quality oil resistent nitrile rubber