Solutions · Sustainable Solutions
Bolting that holds pressure, heat and H₂S, and racking that holds the array
Flange bolting for refineries and gas plants, plus mounting structures, balance-of-system and earthing for utility-scale and rooftop solar.
The problem
A flange joint leak is not a fastener problem until it is. Wrong grade for the temperature, hardness above the sour-service limit, or a coating that changes the friction factor mid-torque sequence. On the solar side the failure is quieter: tracker hardware that backs off under daily articulation, or racking specified for a European wind case rather than a Saudi one.
How MST answers it
MST supplies flange bolting to ASTM A193 / A194 with heat-specific certification and hardness reporting where required, and solar structures specified to the site's own wind and thermal case with serrated flange hardware that stays tight through daily cycling.
Product lines
What sits inside this solution
Browse the solution by family. Each line is supplied against the standard named on your specification, send the clause and we will confirm the grade and the certification route.
Flange & pressure bolting
- Stud Bolts & Heavy Hex Nuts
- Sour Service & Hardness-Controlled Bolting
- Low-Temperature & Cryogenic Bolting
- Exotic Alloy Fasteners
- Insulating Gasket & Sleeve Kits
Solar mounting systems
- Rooftop Mounting Rails & Ballast Systems
- Ground-Mount & Carport Structures
- Tracker & Torque Tube Hardware
- Module Clamps & End Clamps
Balance of system & protection
- DC Connectors & Solar Cable
- Combiner Boxes & Isolators
- Earthing Rods & Exothermic Welding
- Lightning Protection Systems
Product schedule
Representative supply range
Indicative of normal stock and made-to-order supply. Project-specific grades, lengths and coatings are confirmed against the approved submittal before order.
Stud Bolt, fully threaded
ASTM A193 Gr. B7
- Material
- Chromium-molybdenum alloy steel, Q&T
- Size
- M12 – M100 / ½ in. – 4 in.
- Finish
- Plain, PTFE / Xylan, HDG
Stud Bolt, sour service
ASTM A193 Gr. B7M (≤ 235 HB)
- Material
- Cr-Mo alloy steel, hardness controlled
- Size
- M12 – M64 / ½ in. – 2½ in.
- Finish
- Plain, PTFE, zinc-nickel
Heavy Hex Nut
ASTM A194 Gr. 2H / 2HM / 8M
- Material
- Carbon, alloy and austenitic stainless
- Size
- M12 – M100 / ½ in. – 4 in.
- Finish
- Plain, PTFE, HDG over-tapped
Low Temperature Stud Bolt
ASTM A320 Gr. L7 / L7M
- Material
- Alloy steel, Charpy impact tested
- Size
- M12 – M64
- Finish
- Plain, PTFE
Exotic Alloy Fastener
UNS S31803 / S32750 / N06625
- Material
- Duplex, super duplex, Inconel
- Size
- M10 – M56, made to order
- Finish
- Pickled & passivated
PV Mounting Rail
EN AW-6005A T6
- Material
- Extruded aluminium
- Size
- 3.3 / 4.4 m lengths
- Finish
- Mill or anodised
Solar Torque Tube / Tracker Bolt
ISO 898-1 Class 8.8, DIN 6921
- Material
- Carbon steel, flange head serrated
- Size
- M8 – M20
- Finish
- HDG, zinc flake (Dacromet class)
Copper-Bonded Earth Rod
IEC 62305 / BS EN 62561
- Material
- Copper-bonded steel core
- Size
- Ø14 – Ø20 mm × 1.2 – 3.0 m
- Finish
- 250 µm copper bond
Sizes shown are the standard supply envelope; larger diameters and non-standard lengths are produced to order. All grades are supplied with EN 10204 3.1 inspection certification referenced to the heat number unless otherwise agreed.
Product profiles
The profile families in this basket.
Article codes, stocked sizes and stock lengths, as they appear in the catalogue a specifier orders from.
Tree grille profiles
Tree pit grilles and guards for streetscapes and public realm, protecting the root zone while keeping the footway trafficable.
- Materials
- Cast iron, steel and aluminium
Made to the project drawing rather than to a stock schedule. Send the detail and we will section it.
Bollard profiles
Fixed, removable and illuminated bollards for access control and pedestrian separation in public realm and vehicle circulation zones.
- Materials
- Stainless steel and galvanised steel
Made to the project drawing rather than to a stock schedule. Send the detail and we will section it.
Sizes shown are the stocked increments, not the limit of what can be sectioned. Each family also has its own catalogue with the full dimensional drawings; ask for the ones relevant to your package.
Flange bolting, grade selection by service temperature
The temperature envelope is the first filter on a flange bolting grade, before corrosion and before cost. Nut grades must be matched to the stud, not selected independently.| Stud grade | Matched nut | Service range | Selected for |
|---|---|---|---|
| A193 B7 | A194 2H | −46 °C → 400 °C | General process piping |
| A193 B7M | A194 2HM | −46 °C → 400 °C | Sour service, hardness capped |
| A193 B16 | A194 Gr. 7 | → 538 °C | High temperature, steam service |
| A193 B8 Cl. 2 | A194 Gr. 8 | −196 °C → 538 °C | Corrosive, cryogenic |
| A193 B8M Cl. 2 | A194 Gr. 8M | −196 °C → 538 °C | Chloride-bearing, marine |
| A320 L7 | A194 Gr. 4 / 7 | → −101 °C | LNG, impact-tested |
| A320 L7M | A194 Gr. 7M | → −101 °C | Low temp + sour |
Ranges are the commonly applied service envelopes, not absolute code limits. Confirm against the line class, the flange rating and any client engineering standard before ordering.
Applications
Where this is used
- ASME B16.5 / B16.47 flange joints on process piping
- Heat exchanger, valve and pressure vessel bolting
- Sour service per NACE MR0175 / ISO 15156
- Utility-scale PV tracker, torque tube and module hardware
- Rooftop and carport PV mounting
- Substation earthing and lightning protection
Environment & finish
Corrosion strategy, by site condition
The Kingdom is not one environment. The finish that lasts twenty years in Riyadh will fail inside a warranty period on the Gulf coast.
Sour service
B7M studs with A194 Gr. 2HM nuts, hardness controlled to the NACE MR0175 / ISO 15156 limit and reported per heat. Hardness testing and PMI are supplied as part of the documentation package, not as an extra.
Desert PV plant
For Sudair-class solar sites the driver is abrasion and thermal cycling, not immersion, pre-galvanized and HDG carbon steel hardware with serrated flange nuts to resist back-off under daily tracker movement, and A2 stainless at module-clamp level. Aluminium rail and steel fixings are isolated to prevent galvanic attack.
Governing standards
What this discipline is measured against
- ASTM A193 (B7 / B7M / B16 / B8M)
- ASTM A194 (2H / 2HM / 7 / 8M)
- ASTM A320 (L7 / L7M) low temperature
- NACE MR0175 / ISO 15156
- ASME B16.5 / B16.47 / PCC-1
- IEC 62305 lightning protection
- EN AW-6005A T6 aluminium rail
- SBC 301 wind loading
Where a project specification calls out a standard not listed here, send the clause reference with your enquiry, the technical desk will confirm equivalence or source to the named standard directly.
How we source
Three corridors, one certification regime.
Where a line comes from changes its lead time, its certification route and its landed cost. We state the corridor openly rather than hiding it behind 'globally sourced', it is usually the first thing a procurement manager needs to know.
Europe, UK & USA
Germany · Italy · UK · USA
Western-spec lines where the consultant names an EN or ASTM source mill, and ETA-assessed anchors and facade systems.
Gulf & Kingdom
KSA · UAE
Local manufacture and stock for programme-critical lines, with the shortest lead time and full local content and Saudization credentials.
Asia & Türkiye
China · Taiwan · Malaysia · Türkiye
Volume manufacture on certified lines where the specification permits it, same certification regime, tested and documented to the same standard.
Other disciplines
Explore the rest of the range
Civil Solutions
Structural bolting, anchor bolt assemblies, rebar couplers and formwork accessories, with the waterproofing, tanking and thermal insulation around the concrete.
Construction Chemicals
Admixtures, non-shrink grouts, repair mortars, anchoring adhesives, sealants and industrial flooring, the chemistry that makes the mix work at 45 °C.
MEP Solutions
Beam clamps, threaded rod, channel support, cable containment, pipe fixings and plumbing systems, the support and distribution layer, drill-free where the structure allows.
Send us your specification
Send the bolting schedule or specification section. We return grade confirmation, finish recommendation, lead time and certification route.