Corrosion-resistant fasteners for Pulp & Paper Mills.
Corrosion-resistant studs, cover sets and equipment screws for mill water, bleaching and chemical-handling duties.
Which fasteners fit your pulp and paper mill applications?
BYBOLT supplies Duplex 2205 stud bolts for strong, chloride-resistant mill-water connections, Hastelloy C-276 stud & nut sets for aggressive chemical-stage covers and 904L hex bolts for acid-handling equipment. 316L socket head screws provide compact fixings for wet-end machinery. Order the parts for each mill area with its own alloy and drawing requirements.
Fasteners for mill process equipment.
Continuous & batch Kraft digesters
Hot alkaline liquor and sulphide attack digester shell joints, loosening weaker bolting under cyclic cooking pressure. Duplex 2205 digester studs resist caustic cracking while holding preload through repeated heat-up and blow cycles.
Duplex 2205 digester studsRelated material guides
Connection requirements
- Flange facing and gasket type
- Stud length and thread engagement
- Bolt tightening sequence
Bleach-plant washers & mixers (ClO2)
Bleach-plant washer and mixer covers can expose external bolts to chloride-bearing liquor and cleaning residues. 254 SMO hex bolts address this wet corrosive exposure while retaining a head that maintenance teams can counterhold with standard sockets. The cover load and finished-bolt properties determine the required diameter and bolt count.
254 SMO Hex BoltsRelated material guides
Connection requirements
- Bleaching and cleaning chemistry
- Cover load and bolt properties
- Head access and grip length
Black-liquor evaporators & concentrators
On evaporator cover hardware, duplex washers form replaceable seats beneath the nuts. 2205 is useful where the liquor and cleaning chemistry are compatible with the alloy. Smooth, flat faces distribute the nut load, while the exposed outer edge and underside are the locations most likely to collect process residue.
Duplex 2205 Flat WashersConnection requirements
- Liquor and cleaning exposure
- Nut footprint
- Face finish, thickness and flatness
Recovery boiler & causticizing hardware
600 hex bolts are candidates for causticizing covers and brackets exposed to hot alkaline liquor. The useful property is resistance to the local caustic environment at the loaded fastener. Selection follows liquor concentration and temperature, including exposure during cleaning and servicing.
Inconel 600 Hex BoltsRelated material guides
Connection requirements
- Hardware joint thickness, gasket type, and required preload
- Bolt diameter, grip length, and nut/washer stack-up at installed position
- Hot caustic exposure, cycling duty, and heat-number certification
Paper-machine wet-end & suction rolls
Acidic white water and continuous vibration fatigue wet-end roll joints, loosening fasteners under cyclic bending loads. Duplex 2205 roll screws maintain clamp load while resisting corrosion fatigue in wet suction-roll service.
Duplex 2205 roll screwsRelated material guides
Connection requirements
- Suction-roll journal bolt fit
- Roll-shell flange alignment
- Vibration-resistant locking method
Tall-oil & chemical recovery piping
SMO 254 tall-oil piping bolts combine molybdenum-rich pitting resistance with reliable sealing for chemical recovery lines. Their austenitic strength holds gasket compression through thermal cycling and aggressive tall-oil and condensate exposure.
SMO 254 piping boltsRelated material guides
Connection requirements
- Pipe flange facing and gasket type
- Bolt length and thread engagement
- Joint alignment and support spacing
Chlorine dioxide, hot caustic, vibration.
Bleach-stage fasteners face different combinations of chlorine dioxide, acidity and chloride deposits. C-22, C-276 and Titanium Grade 2 are options for appropriate wetted duties; compare stage-specific corrosion data before using 316L in sheltered threads.
What to specify
- Chlorine dioxide concentration
- Chloride content
- Service temperature
Hot caustic can cause stress-corrosion cracking, with concentration and metal temperature setting the risk. Compare 2205, 2507, 600 and 625 using the actual liquor and bolt condition; higher chloride-pitting resistance does not automatically mean better resistance to hot caustic.
What to specify
- Black-liquor concentration
- Service temperature
- Applied tensile stress
2205 roll screws combine strength with corrosion resistance in suitable wet-end water. 17-4PH offers higher strength for protected loaded attachments, but its aging condition and corrosion exposure matter. Set the thread geometry and preload for the actual vibration and load cycle.
What to specify
- Vibration frequency
- Cyclic bending load
- White-water pH
Compare pulp & paper fastener alloys.
| Material grade | Mechanical Duty / Focus | Environment | Relative cost | Popular fastener forms |
|---|---|---|---|---|
| Duplex 2205UNS S32205 / S31803Duplex stainless |
| Recirculating mill water and chloride-bearing wet-end circuits | $$ |  Stud bolts |
| Hastelloy C-276UNS N10276Mixed-acid resistance |
| Bleach-stage liquors and chemically aggressive condensates | $$$$ |  Stud & nut sets |
| 904L stainless steelUNS N08904Acid resistance |
| Sulfuric-acid utility streams and contaminated process liquids | $$ |  Hex bolts |
| 316L stainless steelUNS S31603Low-carbon stainless |
| Low-chloride wet-end equipment and external washdown | $ |  Socket screws |
Budget guide: $ lower · $$ moderate · $$$ higher · $$$$ premium. Relative raw-material bands; dimensions, quantity, processing and inspection determine the finished-fastener quote.
Material & cost references
- Nickel Institute — Pulp and paper applications
- Haynes International — Chemical processing alloys
- Alleima — SAF 2507 material data
- Outokumpu — Ultra corrosion-resistant stainless steels
- Alleima — SAF 2205 material data
- Nickel and specialty-alloy round-bar price comparison
- Stainless-steel supplier price ranges
- 800H round-bar supplier price range
- Alloy 20 round-bar supplier price range
Cost bands group overlapping published supplier ranges for initial budgeting; they are not live BYBOLT prices. Specify the exact UNS and final condition on the order.
2205 may be ordered as S32205 or S31803; identify the required UNS on the order.
Mill pump studs, cover bolts & equipment screws.
Duplex 2205 stud bolts
Combine strength and chloride resistance at mill-water pump covers and process connections.
Hastelloy C-276 stud & nut sets
Resist aggressive chemical attack at bleach-stage and evaporator covers, with matching nuts supplied together.
904L hex bolts
Provide acid-corrosion resistance at sulfuric-acid utility and chemical-distribution connections.
316L socket head screws
Secure accessible wet-end machine covers with a compact recessed drive and washdown corrosion resistance.
Mill pump & cover maintenance kits.
Consolidate shutdown hardware by mill area while keeping the different chemical-service alloys clearly separated.
Mill fastener traceability & inspection.
EN 10204 3.1 MTC, heat traceability and mechanical test results with each shipment. Add the tests your equipment specification requires.
Material identity
Match the ordered grade and material heat to the certificate, part identification and packing list.
Final condition
Link the specified processing condition and mechanical results to the finished batch; keep separate heat-treatment batches identifiable.
Drawing dimensions
Stage, asset tag and drawing revision.
Stage-specific acceptance
Identify any corrosion test or customer acceptance requirement for the actual liquor and mill stage.
Before you order pulp & paper fasteners.
Send the drawing and the service details for your connection. We can quote the specified parts, finish and inspection package together.
Get a QuoteWhy is the bleach-stage designation needed?
It identifies the chemistry the connection actually sees. Include residual oxidant, chloride, pH and temperature so the alloy comparison follows that stage rather than a general paper-mill label.
Can you quote a mixed-material mill shutdown list?
Yes. Keep the equipment tag, material condition and drawing revision on each line. We can group the matching components and records by maintenance assembly.
What helps with corroded wet-end fasteners?
Send the water and cleaning chemistry, photographs of deposits or attack, and the mounting section. Identify whether damage occurs on exposed surfaces or beneath the head and washer.
Send your drawing
or parts list.
Upload the drawing or BOM with its revision. We quote the material, dimensions, quantities and inspection requirements for your equipment.
Mill stage/equipment tag, liquor or water chemistry, residual oxidant/pH where relevant, temperature, drawing and quantities…
