NTV Scientific & Technical Firm has been engaged in the restoration, repair and modernization of worn-out screws, screw-and-barrel systems and material cylinders of extruders (screw extrusion machines, automatic molding machines, presses, injection molding machines, pelletizing machines, mixers) of domestic and foreign production with diameter of 38 mm and a length of up to 8,500 mm.

Experience of repair of screws, according to our technology, at enterprises producing tires (10 tire factories), industrial rubber products, chemical fibers and plastic products (more than 1,100 enterprises in 52 regions of the Russian Federation), the food industry (more than 30 enterprises in 11 regions of the Russian Federation) allows us to speak about full restoration of their performance and service life period at the cost of repair that is significantly less than the cost of new parts.

Technical characteristics of our technology for the restoration and repair of screw crests on outside diameter.

  • Deposition of screw crests on outside diameter onto the semi-solid substrate of hard alloys with high wear resistance under conditions of dry friction in metal to metal contact, high corrosion resistance (also in the nitric acid environment) and high resistance to abrasive wear. Surface hardness after deposition, depending on the material used, is 30–60 HRC.* Type of deposited material is selected based on the working conditions of the part.

  • Grinding is carried out on the outside diameter with a tolerance range of 0.05–0.15 mm.

  • Side surfaces of the crests are processed with roughness of 0.63 Ra.

  • Surface shape tolerances are observed (cylindricity of outside diameter of the screw crests).

  • Surface location tolerances are observed (alignment, end face and radial runout of the outside diameter of screw crests in relation to the drive shank).

* We draw your attention to the fact that high hardness of the deposited materials on the screw crests is not the determining and the only factor of high wear resistance of both the screw and the screw - material cylinder system. Wear resistance of the system is determined in total by a combination of such factors as: scoring resistance (heat resistance), corrosion resistance, abrasive resistance of both surfaces in the friction couple.

For more than 25 years of work, in addition to the standard restoration of the outside diameter, we have conducted many types of additional repair work on screws

We are able to restore the following on a high quality level:

  • body of the screw

  • fully worn-out crest

  • sealing zones

  • mixing zones

  • barrier zones


  • cracks

  • broken screws

  • shanks

  • mounting seats for bearings

  • threads

  • tips

  • lockrings


  • screw configuration

  • body and crests of the screw by armoring


Screw Ø45 mm before restoration

Screw Ø45 mm after restoration

You can find more detailed examples of executed works in the gallery of works

Шнек до восстановления

Injection molding screw Ø70 mm before restoration

Восстановленный шнек

Injection molding screw Ø70 mm after restoration

вост цилиндр.png

* In case of urgent need there is a possibility of accelerated repair of the screw.

We provide a guarantee for the restoration and repair of the screw.