A steel or pre-engineered building (PEB) needs fasteners at every stage: foundation bolts in the footings, high tensile bolts in the frame, anchors for later fixings and threaded rods for services. This page lists the fasteners such work usually needs. JMIKS Fasteners supplies them from Ahmedabad.
| Typical fastener | Material or grade | JMIKS product link |
|---|---|---|
| Column foundation bolts | Mild steel 4.6 / 5.6 or high tensile 8.8; self colour or HDG | J Bolt, L Bolt |
| Main frame connections | High tensile 8.8 or 10.9 | Hex Bolt |
| Nuts for frame bolts | Class 8 for 8.8, class 10 for 10.9 | Hex Nut |
| Purlin, girt and bracing bolts | 4.6 or 8.8, hot dip galvanized or zinc plated | Hex Bolt |
| Fixings to existing concrete | Mild steel or stainless steel anchors | Wedge Anchor, Sleeve Anchor, all anchors |
| Hangers for pipes, ducts and cable trays | Threaded rod 4.6 / 8.8, zinc plated or HDG | GI Threaded Rod, Long Nut, Bullet Anchor |
Grade 8.8 is the usual high tensile grade for main frame connections such as end plates, splices and haunches; 10.9 is used where the design asks for more strength. Purlins and girts take smaller bolts, M12 being common, in 4.6 or 8.8. Steel design in India follows IS 800, and your drawing gives the size, grade and tightening method.
Pair every bolt with a nut of the matching class: class 8 for 8.8 and class 10 for 10.9 (ISO 898-2). A weaker nut can strip before the bolt reaches its load. Fit a plain washer under the part that is turned. Read more on high tensile bolts and in our bolt grade chart.
Friction grip (HSFG) joints are different. They use a matched set of IS 3757 bolts, IS 6623 nuts and IS 6649 hardened washers, tightened to a set preload under IS 4000. If your drawing calls for HSFG bolts, say so in your enquiry, because ordinary hex bolts are not a substitute.
Column bases are held by J bolts or L bolts cast into the footing with a template; our foundation bolts guide explains setting and ordering. For fixings added later, such as stair brackets, canopies and machine bases, use wedge anchors in solid concrete or sleeve anchors in concrete, brick and stone, following the anchor’s installation data for hole size, depth and edge distance.
Pipes, ducts, cable trays and sprinkler lines hang from threaded rods: grade 4.6 for general use and 8.8 for heavy loads. Fix them to the slab with bullet (drop-in) anchors, join lengths with long nuts, and lock each support with hex nuts. Rods come in full lengths of 1 m, 2 m and 3 m, or cut to size.
Use hot dip galvanized bolts and nuts on exposed and outdoor steelwork, and zinc plated parts indoors. HDG nuts are tapped oversize, so never fit them on plain or zinc plated bolts. ISO 10684, the standard for galvanized fasteners, stops at class 10.9, and some specifications do not allow 10.9 bolts to be galvanized because of the risk of hydrogen embrittlement.
Main frame connections usually use high tensile 8.8, or 10.9 where the design needs it, and purlins and girts use 4.6 or 8.8. The drawing decides.
A class 8 nut, or a higher class. Use class 10 nuts with 10.9 bolts. A nut of a lower class can strip.
HSFG bolts are tightened to a set preload, so friction between the plates carries the load. They need matching IS 6623 nuts and IS 6649 hardened washers. Ordinary bolts carry the load in shear and bearing.
Only if the structural engineer agrees. Cast-in bolts are designed for the column loads, while drilled anchors suit fixings added later.
Send your bolt list or drawing, with sizes, grades, finishes and quantities. Message us on WhatsApp at +91 90333 11425 or use our enquiry form, and we reply within one working day. See the full range in our catalogue (PDF).
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