The tyre segments wrap the working roll of a briquetting, compaction or granulation roller press, forming the pockets and lands that compress powder into a sheet, briquette or flake. Because the tyre operates under multi-tonne-per-centimetre roll force with the product sliding through the nip, it needs both a hard working face and a tough core. Ningbo Ruican investment casts the segmented tyre body and CNC machines the roll-side seating surfaces, stud seats and segment joint faces so the assembled ring runs true.
Specifications
| Specification item | Detail |
|---|---|
| Casting process | Silica sol investment casting for thin section control near pocket profiles; water glass process for heavy, larger format segments |
| Material options | Through-hardened AISI 4340 and 4140 alloy steel, AISI H13 tool steel, high-chrome white iron, duplex stainless for corrosive feed stock |
| Dimensional tolerance (ISO 8062-3 CT grade) | CT6 standard with silica sol; CT7 with water glass; critical seats finish machined to drawing tolerance |
| Machining | CNC milling and grinding of roll-side seat radius, joint faces, stud seats and locating keys; bolt holes drilled in fixture |
| Surface finish (Ra) | As-cast Ra 6.3 um maximum; machined seat radius Ra 1.6 um; joint faces Ra 0.8 um for true ring assembly |
| Hardness / heat treatment | Quench and temper to 45-58 HRC core depending on grade; induction hardening of working face to 58-62 HRC optional |
| Weight range | 15 kg to 220 kg per segment |
| Typical lead time | Tooling 30-40 days; first article samples 40-55 days; production 45-60 days including machining and inspection |
Key features
- Segmented design lets operators replace worn sectors instead of discarding an entire roll tyre ring.
- Cast and machined seat radius matches the roll body so the segment beds fully and does not fret under load.
- Differential hardness strategy gives a wear-resistant working face with a tough core that resists pocket cracking.
- Precision joint faces keep adjacent segments aligned, preventing the step that marks the product sheet.
- Optional induction-hardened working face for very abrasive mineral fines and ash compaction duty.
- Pocket profile cast to near net shape, reducing expensive pattern-welding or EDM stock removal.
Applications
- Briquetting roller presses for coal, charcoal and mineral fines
- Compaction granulation presses for fertilizer and potash production
- Roll presses for salt, soda ash and chemical flake production
- Hot briquetting of metal chips and swarf in recycling plants
- Lime and cement raw meal compaction circuits
- Pharmaceutical and agrochemical dry granulation roll compactors
Quality & compliance
Each segment ships with EN 10204 3.1 certification relating chemical analysis and mechanical properties to the stamped heat number on the back face of the casting. Hardness is mapped across the working face, the pocket root radius and the seat radius, and the values are reported per batch so any deviation from the hardness envelope is visible before assembly. Dimensional reporting covers seat radius, joint face flatness, stud-hole true position and overall arc length, verified on a coordinate measuring machine and cross-checked against the roll body drawing supplied by the customer. Ultrasonic examination of thick sections and magnetic particle inspection of the pocket roots are available. First article inspection and PPAP documentation are prepared on request under our IATF 16949 certified system.
FAQ
How many segments make up a full tyre ring?
Most roller presses use four, six or eight segments per ring, depending on roll diameter and the maintenance lift available at site. We manufacture to whatever segment count the press builder specifies, and we index the joint faces so the assembled ring closes without gaps. Share the roll diameter and segment count requirement and we will confirm casting feasibility and tooling layout.
Can you match an existing tyre profile from a sample?
Yes. We commonly reverse-engineer pocket profile, pitch, seat radius and joint geometry from a worn sample plus measurements of the mating roll body. The resulting drawing is submitted for approval before tooling is cut, and it stays confidential to your account. This lets plants keep legacy presses running without buying an entire replacement roll assembly from the original supplier.
What hardness do you recommend for very abrasive potash or ash feeds?
For highly abrasive fines we recommend an induction-hardened working face reaching 58 to 62 HRC over a through-hardened 45 to 50 HRC core. The hard face resists pocket rounding while the tougher core prevents the radial cracks that start at the pocket root. Where the feed is mildly abrasive, a uniformly through-hardened segment is usually more cost effective.
How do you ensure the segments assemble into a true ring?
Segments are machined with the joint faces square to the seat radius in a single set-up, and arc length is verified against the theoretical chord so the ring closes cleanly. Segments are match-marked by ring position. We can dry-assemble the ring in our shop before shipment and record the joint gap and outside diameter runout in the inspection report.
Do you machine the pocket pockets themselves, or only mounting surfaces?
Pocket profiles are cast to near net shape, which removes most stock removal cost. Where the pocket form tolerance or surface finish is tight, we finish-machine with form tooling and verify the profile against the drawing. Our standard quotation states clearly which surfaces are cast and which are machined, so there is no ambiguity about what our machine shop delivers.
What is the expected first article timeline for this part?
Segmented tyre bodies are our longest lead item in this batch because of size, heat treatment and machining content. Tooling runs about 30 to 40 days, first article samples roughly 40 to 55 days, and production series around 45 to 60 days from order release. We provide a dated schedule with the quotation and issue progress updates at tooling, casting, heat treatment and machining milestones.
Send your tyre segment drawing or worn sample, roll diameter, feed material and annual requirement to Wendy She at sales@cnsandcasting.com, or contact her on WhatsApp at +86-13777124360. Wendy will arrange an application review covering alloy, hardness strategy and pocket profile, then return tooling, sample and series pricing with a dated delivery schedule.
