Screw manufacturing and regeneration
MANUFACTURING
Screw manufacturing can be done following samples or by drawings in several materials, with the possibility to make different profile based on material.
REGENERATION
As soon as we receive the used screw we carry out the following checks:
- crest diameter
- thread conditions
- coupling conditions
- kernel wear and coupling diameter
The scope of such verifications is to estimate the operations to carry out, in order to bring back the screw to the original level, operating on the wearied parts, ruined or broken off during the use.
The restoration of the original diameter, essential condition to restore the capability to transport the plastic material to the original level, is done by means of welding material on the crest by means of automatic machines that assure a homogenous welding and absence of blows.
After that there is a finishing and final polishing, which assure a final rugosity lower then 0,06RA. There are several materials for repairing and the choice is based on customer requirements.
OVERLAYS
| Overlay | Hardness | Wear resistance (1-5) | Corrosion resisteance (1-5) |
| Stellite Gr.1 | 50-55 HRC | 4 | 3 |
| Stellite Gr.12 | 45-48 HRC | 3 | 3 |
| Castotig 5 | 58-62 HRC | 5 | 3 |
| Base Nikel 56 | 52-55 HRC | 4 | 5 |
MATERIALS:
- Nitrited steel (41CrAlMo7) 60 HRC
It is a steel, with aluminium, chrome, molybdenum which, during the heat treatment, create nitruri very strong, which rise hardness of 1050 HV approx. This material is suggested where there are not problems of corrosion and wear. - Hardened steel (X155CrMoV121) 58-60 HRC
It has a very high percentage of chrome, which gives a good strenght and long life. This material is suggested where there are wear problems.
Life: 2-3 times standard nitrided - Hardened steel to 60-62 HRC – Isotrix
This hardened steel has an high percentage of chrome, tungsten, vanadium which guarantee a very high resistance to wear and corrosion. These characteristics can give a life longer than a plasticized screw build in X155CrMoV121
Life: 4-5 times standard nitrided - (X155CrMoV121) with CLIN-NIVE 1200 Vichers
CLIN-NIVE is an heat treatment for italian market only (for plastic stamping) which increase screw performances in terms of resistance to abrasive and corrosive materials with no impact in cost
Minimum delivery time: 6 working weeks - Sintered steel
Sintered steel screws complete our product range. These materials are chosen according to product characteristics to be processed, granting screw lifetime equal to 12 times of nitrided steel screws.
