HMG Extrusions - Screws & Barrels Refurbishing

SCREWS REFURBISHING PROCESS:

1. Old screws received will be cleaned and all dimensions checked and remeasured
2. 0,5 mm (1,0 mm on the diameter) of the nitrided layer will grinded and taken off.
3. The edges of the flights will filed of by 0,3 – 0,5 mm
4. As a preparationn of the coating the bottom and side of the screw flights will be 
   covered with special material.
5. Both screws will be sandblasted
6. Apply of Plasma coating (Molybdenum) by means of spraying with an oversize
   of 0,3 mm.
7. Then the edges of the flights will be grinded.
8. The coverage will be taken off manually.
9. The plasma coated layer will be sealed with a special glue.
10. All surfaces (bottom, sides) will be polished.
11. Flights will be grinded to exact dimension required.
12. Screws look and perform like new.

BARREL REFURBISHING PROCESS:

1. Barrel received will be cleaned and all dimensions checked and remeasured
2. The diameter of the bore-hole will be grinded to maximum of 0,5 mm
3. nitriding of the complete barrel (layer of  0,6 mm)
4. polishing of the bore hole and of the flanges
5. Dimensions checked according to ISO standard.
6. Barrel look and perform like new.