Pop rivet query

[Little Jerry]

Gents

Can anyone tell me what type of pop rivet this is? On the outside it looks like any other pop rivet but on the inside it looks like below. This was on a heater box in a Ford F150. Any reason why this type would be used as the heater box - looks like it might give a better seal than a standard rivet but the funny thing is that it had other rivets that look like your standard pop rivet. The only other thing I could think is that it may have been used for extra clearance as the heater box flappers move in that area?

 

[DanZac]

They look like a normal (tucker pop) blind rivet with a washer on the back to spread the load and stop the tail from pulling through.

 

[Little Jerry]

Im an idiot...you are right...i thought the washer was part of something that was crushed on the other side but upon closer inspection the washer is seperate from the rivet.

 

[Little Jerry]

While I am asking dumb questions....is there a name for this type of self tapping plastic screw that seems to have alternating thread size?

 

[frank horton]

dont know the name but a lot of Yank stuff has fasterners for untapped holes and ease of assembly....
used especially around garden machinery....trucks etc....
they just drill a hole the right size and ram these screws in with a big driver....
partiq suited to unskilled, cheap labour....

 

[Seadog]

Try searching for "Twinfast."

Hi Lo CSK Head | Fastenright Ltd

Hi-lo thread countersunk head self-tapping screw for plastic. Thread forming screws in stock in range of sizes. Specials to order, send your requirements.

www.fastenright.com

High-Low Self-Tapping Thread Screws - Mutual Screw & Supply

www.mutualscrew.com

 

[pedrobedro]

This was on a heater box in a Ford F150. Any reason why this type would be used as the heater box -

They do it to stop the rivet enlarging the hole in softer material and pulling the mandrel through.