What these fabrications are used for
Steel hoppers, bins and chutes move bulk solids through a process line. A buyer specifies them when a machine, silo, batching plant or conveying system needs a custom interface that no catalogue part fits. Common cases are aggregate and cement handling, mineral and ore processing, and the feeding or collecting points on conveyor and screening equipment.
Realjet supplies this type of work as contract manufacturing built to the buyer's drawings and specifications. The parts are fabricated steel, not precast concrete, and the value sits in holding tight geometry at welded joints, lining the wear surfaces, and matching the machined mounting faces on the adjacent equipment.
Drawings and data the buyer must supply
A usable request starts with the drawing package. At minimum the supplier needs the overall profile, the plate thickness schedule, the material grades, and the tolerance blocks for critical dimensions. For outlets and flange faces the buyer should mark the mating standard or attach the mating part drawing, so the machined interface is cut to the right pattern.
Two items decide whether a quotation is firm or provisional. The first is the discharge geometry: diameter, flange class or bolt circle, and any skew or offset. The second is the support and lifting scheme, because a tall bin carries its load into the structure through defined points that must be drawn, not assumed. When these stay open, the supplier can only give a range and rework risk moves to the buyer.
Material, plate and wear protection
Most hoppers use structural plate such as ASTM A36 or A572, with higher grades where fatigue or impact matters. Where the conveyed material is abrasive, the buyer should call out a wear plate or liner on the zones that take the load. That choice changes both the welding sequence and the inspection plan, so it belongs in the specification rather than in a later note.
Material traceability is the buyer's safeguard. Ask for mill test reports that name the grade and heat, and confirm the supplier can keep them with the job record. This matters when the part serves a regulated plant or a client audit.
Welding scope and acceptance
Welded plate naturally introduces distortion, and a hopper's straightness at the outlet decides whether it seats. The buyer should state the welding code, commonly AWS D1.1 for structural steel work, and the inspection level. ISO 3834 sets the welding quality system behind the procedure, and EN 1090 applies where the part carries a CE marking in the European market. These are general industry references, not Realjet performance claims.
Decide early which welds are subject to nondestructive testing and to what extent. A full penetration weld on a thin cone costs more than a fillet weld and needs a qualified procedure, so the drawing should mark the joints that truly need it. Where the buyer leaves this open, expect the supplier to quote a conservative default and add cost.
Machined interfaces and outlets
The outlet is where most field problems start. If the hopper bolts to a feeder or valve, the flange face must be machined flat and the bolt holes pitched to the mating part. State the surface finish and flatness, and supply the mating drawing so the supplier machines to the real pattern rather than a generic one.
For sliding or rotating interfaces, such as a gate seat, the buyer should define the bearing surface and any hardfacing. These are machined features, and the drawing should show them as such instead of leaving them to shop interpretation.
Surface treatment and coating
Exposure decides the coating. An indoor, dry duty may need only a primer, while an outdoor or corrosive duty needs a full paint system with agreed DFT and surface preparation such as Sa 2.5 blasting. Put the coating specification in the request so the shop can plan blasting, welding repair and final paint in the right order.
Inspection, documentation and packing
Before shipment the buyer should agree on what evidence closes the order. Typical records are the material certificates, the welding procedure and procedure qualification, the inspector's report for any tested welds, and a dimensional check at the interfaces that matter. If the part ships overseas, the packing method and lifting points should be agreed in writing, because a bin that arrives bent costs more to fix than to protect.
How to start a request for quotation
Collect the drawing set, the material and lining spec, the welding code and inspection level, and the outlet mating data. Buyers who want a single fabrication partner for welded and machined steel work can review the contract manufacturing services and the related note on welding procedure and NDT requirements before sending the package. A complete submission gets a firm price and a shorter lead time than a drawing with open interfaces.