>>> SAFETY ALERT <<<< PRODUCT WARNING
Re: Frame Rivets for stamped receiver Kalashnikov type rifles.
K-VAR Corp. is providing this information in response to a significant number of inquiries concerning the general use of rivets used to affix and secure the trunnion and rear blocks to the frame on all stamped receiver AK type rifles.
The most important thing to know about this subject is THESE RIVETS HOLD THE ENTIRE FRAME TOGETHER and are crucial to the structural integrity of the frame.
That makes these very small parts very important. The quality of material and correct dimension and configuration of these parts is vital to the safe use of your firearm.
As you know, when in proper working order a firearm in action is basically a controlled and contained rapid expansion of gas and pressure that expels a projectile out of the muzzle.
If that control and containment is compromised, then a jam is the least of your worries. Improperly contained this discharge quickly turns into a disaster.
So, what does this have to do with rivets? What difference does it make? Once again, THESE RIVETS HOLD THE ENTIRE FRAME TOGETHER.
Below are some of the questions asked and responses by our technical staff. Please read these advices. It’s important for your safety.
Q.: Why all of this debate over a part as simple as a rivet?
A.: When the stamped receiver AK was first developed and fielded, significant shortcomings of the design began to appear (ie...the rivets sheared off and the frames feel apart after repeated firing).
As a result, for some time, production of the stamped receiver version of the AK was suspended. After lengthy R&D the source of the shearing was isolated and a solution found. The flat bottom of the rivet allowed movement of the frame components during firing. These components (namely the frame) got looser with each successive impact of the action parts in movement until the rivets sheared off and the frame failed.
The solution was to redesign the rivet head to include a beveled or chamfered head bottom that in turn locked into the frame and trunnion blocks when attached. This created a solid bearing surface which firmly lodged the rivet and prevented shearing.
Solution found, the stamped receiver went into full production and AKs filled the world.
Q.: What’s the difference? A rivet is a rivet.
A.: Not actually. In a proper rivet set for the AK (depending on country of origin) there are up to 6 (six) different styles of rivet used.
The dimensions and individual style of the different types have a specific location and configuration to perform a specific function and are not interchangeable. Improper installation or using incorrect rivet parts will result in catastrophic failure at the rivet attachment points.
But, it gets worse.
If the rivet material is incorrect, the problem magnifies. If the metal used in a improperly shaped rivet is too hard or soft on the Rockwell scale, then the catastrophic failure happens all the sooner. The wear or shearing that occurs is magnified and accelerated if the Rockwell property doesn’t match the specific material specification required.
The combination of incorrectly shaped rivets that allow shifting and additionally do not conform to the material specification is a recipe for disaster.
See attached illustrations for clarification.
Q.: So, what are the different rivet configurations for the various AKs?
A.: The three most common configurations are:
Romanian (14 total)> 2 long chamfered, 1 long thin flathead, 5 short roundhead flat bottom, 4 short chamfered roundhead, 2 short flathead chamfered.
Bulgarian (15 total)> 1 flattop long chamfered, 2 short chamfered roundhead, 1 long thin flathead, 4 short roundhead flat bottom, 1 short heavy cylinder head, 4 short chamfered roundhead, 2 short flathead chamfered.
Bulgarian-side folder (17 total) > 1 flattop long chamfered, 4 short chamfered roundhead, 1 long thin flathead, 4 short roundhead flat bottom, 1 short heavy cylinder head, 4 short chamfered roundhead, 2 short flathead chamfered.
Q.: I’ve seen less expensive rivet sets from other vendors.
A.: Yeah, we’ve seen them too, even purchased some to compare to our products. Frankly, the one’s we’ve examined just won’t work.
Let me clarify that statement.
They will work, but, the result will be eventual catastrophic failure due to the causes we’ve outlined above.
Simply put, I wouldn’t use them on my gun.
What you need to decide when purchasing a rivet set in regards to price is A. Will the lower priced product you intend to buy be inferior or dangerous & B. Is your life worth $5.00?
We hope this clarifies some of your questions. Your safety is important to us.
K-VAR Tech Department
As You can see the K-VAR rivet Sets include the correct center support rivet
(support sleeve shown in illustration is for refference purposes only and is available as AK-156B).
Offerings by other companies incorrectly include only a short rivet which does nothing but fill the
hole and provides no support whatsoever.