WE HAVE A DIFFERENT LISTING FOR THESE SCREWS THAT INCLUDES THE T25 BIT FOR A SLIGHTLY HIGHER PRICE. WE HAVE A 100-PACK LISTED IF YOU NEED MORE AND WANT THEM AT A BULK DISCOUNT

DO NOT USE ONE OF THESE SCREWS TO HOLD THE VALVE IN PLACE UNDER HIGH PRESSURE AS SHOWN IN THE PHOTOS. THAT WAS DONE TO DEMONSTRATE HOW STRONG ONE SCREW IS AND WHAT ONE HOLE IN THE TUBE CAN TOLERATE. THIS WAS DONE IN A CONTROLLED ENVIRONMENT BY A VASTLY-EXPERIENCED PROFESSIONAL, IT IS NOT SAFE TO DO YOURSELF AND COULD RESULT IN SERIOUS INJURY, DEATH AND PROPERTY DAMAGE. ALL THREE SCREWS MUST BE CORRECTLY INSTALLED TO HANDLE UP TO 3300 PSI SAFELY.

THESE SCREWS ONLY FIT DISCOVERY MODELS. We have other custom valve screws listed that fit 22XX, Maximus, Fortitude, Marauder Pistol, 1720T and 1701P.

A T25 bit (NOT INCLUDED) is needed to install them. They are direct-fit for Discovery models with the factory plastic trigger casing. If you have our custom rifle group or casing made of metal or a pistol trigger frame, the bottom screw will interfere with the metal trigger casing/frame from seating flush. You can leave a factory screw in that position, it doesn't lower the safety factor significantly to use one factory screw in the bottom position. You can leave the bottom screw out if using 2600 PSI or less. We will include one modified screw instead if you message after ordering. Some prefer to file the screw to the contour of the tube after installing it tight, that is the strongest/safest option but many are not willing or able to do it correctly.

They are designed by Magnum Airpower LLC and custom manufactured, they are not available from any other source. They safely raise the operating pressure to 3000 PSI. They are 410 stainless steel heat treated to meet metric class 12.9 with a specified hardness of HRc 39-43. The approximate tensile strength is 185,000 PSI. The head diameter is .3155", the head height is .0975" and the thread size is 8-32 x 3/16".

The second photo shows one of these screws holding a Discovery valve with 3300 PSI in the tube. The pressure on the gauge is clearly visible in the photo. This is the strongest screw set that exists for Discovery models. These screws can handle much higher pressure than the fill adapter can, the safe pressure limit is based on what the fill adapter can handle with a minimum 3:1 safety ratio which is about 3000 PSI. With our custom fill adapter, assuming your tube is in spec, 3200-3300 PSI is safe.

They are designed to fit the threaded holes very snug when fully-installed. The last 1/64 of an inch requires a little extra force to get the screw head snug against the valve. Do not over-tighten, they should be hand-tight flush against the valve-body with no gap between the head and valve but no more torque than that is needed, be careful not to strip-out the threads in the valve, they are sometimes partially-stripped from the factory to begin with.