Above: 1.5mm "Bulged" trunnion and receiver next to a 1mm trunnion and receiver.
Lots of confusion arises from 1.5mm receivers - Both in terms of the Yugo vs Romanian/Russian models, as well as those unsure if they need a 1.5 or 1mm for their kit.
As the naming suggests, 1.5mm receivers have thicker steel, maintaining the original exterior width of the receiver (other than the bulge we will discuss in a second), but having a thinner interior width due to the thickness of the metal. This means regular 1mm trunnions will not fit in 1.5mm receivers, and Yugo trunnions will have their own issues as well.
Compare the thickness of the receivers - 1.5 on the left, 1mm on the right.
Thankfully, identifying kits is quite easy - just look at the front trunnion. The 1.5mm trunnions have a "bulged" profile on the side instead of the uniform shape of the 1mm trunnions.
This is also quite noticeable in in how the 1.5mm receiver has the extra bends at the front to accommodate this bulged section. This also means that while a 1.5mm trunnion is thinner on the bottom side for the thinner interior of a 1.5mm receiver, will not fit in a 1mm receiver due to the wide bulge section.
1.5mm Trunnion and Receiver
Now that you know what kit you have (in terms of receiver thickness at least), if you have a 1.5mm, you need to choose between the two 1.5mm receivers we offer - you can check out the differences here.
One last note - Chinese receivers use their own receivers as well - 1.6mm.
If you are unsure or have more questions, contact us.