Workshop Manual · Rev A · 2026

Assembly Guide

BPT Model L · 2400 × 1200 × 150mm · 6mm S275 Structural Steel

⏱ Est. build time: 2–4 hours 👤 Solo build: achievable 🔧 Skill level: intermediate

Section 01

Before You Start

⚠

Read this entire guide before picking up a tool. Familiarise yourself with all steps and check you have every component before beginning assembly. Do not attempt to build on an uneven floor — your floor becomes your reference surface. This guide is also applicable to the BPT Model - S, the same construction - just less parts.

What's in the box

Qty	Component	Description
1	Top plate	2400 × 1200 × 6mm S275, full hole grid
2	Long sidewalls	2400 × 150 × 6mm, hole grid both faces
2	Short end walls	1200 × 150 × 6mm, hole grid both faces
3	Brace A	2400 × 150 × 6mm torsion-ribs
2	Brace AA	2400 × 150 × 6mm torsion-ribs
6	Brace B	1200 × 150 × 6mm Cross-length torsion ribs
4	Brace BB	1200 × 150 × 6mm Cross-length torsion ribs
1	Brace BBB	1200 × 150 × 6mm Cross-length torsion ribs
6	Legs	70 × 70 × 3mm RHS, cut to ordered height
4	Corner leg plates	6mm plate
2	Middle leg plates	6mm plate
6	Leg mount plates	6mm plate, pre-cut, weld to legs
6	Leg base plates	6mm plate, pre-cut, weld to legs
24	Fixing sets	M16 x 40mm - grade 8.8 bolts, nuts & washers

Tools required

🔧MIG or TIG welder — for final assembly
🔩M10 threaded rod, nuts & washers — grade 8.8, qty lots!
🔧17mm spanner / socket set — M10 hardware
🔧24mm spanner / socket set — M16 hardware
🔩BPT assembly brackets — for clamping in tension, qty 25
📏Tape measure — diagonal measurement for squaring
🪛Rubber mallet — seating tab & slot joints
⚖️Spirit level — levelling finished table
🥽PPE — welding mask, gloves, steel toe boots

💡 A second pair of hands is helpful for Step 3 (lid placement) but not essential.

Section 02

Step-by-Step Assembly

Unpack and inspect all components

Lay all panels flat on a clean workshop floor. Check every component against the BOM in Section 01. Inspect edges for any transit damage — minor surface marks on raw steel are normal and do not affect structural integrity.

Panels are laser-cut and will have slight burring on cut edges. Wear gloves when handling bare panels. Keep the top plate face-down and protected until it is needed in Step 2.

Check: Hole pattern present on all 5 faces (top + all 4 sidewalls). Count legs — Model L ships with 6. Locate all threaded rods and assembly brackets before starting.

Est. time15 min

Legs6 × 70 × 70 RHS

Joint typeTab & slot lattice

Lay the top plate face-down and build the rib lattice on top

Place the top plate face-down on a flat, clean surface — either on a pallet or steels, just something to raise the plate in the fourcorners with the centre supported, so that you are able to safely access the underside when clamping . The underside of the top plate becomes your assembly datum: everything builds up from it.

Begin slotting the internal ribs together to form the lattice grid directly on top of the plate. Long ribs (cross-length) and short ribs (cross-width) interlock at their half-depth slots — work from the centre outward. The ribs should sit flush against the plate with no gaps.

Important: The rib lattice must sit fully flat against the top plate before the sides go on. Any twist in the lattice at this stage will transfer into the finished table.

Top plate face-down, surface protected
All long ribs slotted together
All short ribs interlocked into lattice
Lattice sitting flat and flush against plate — no rocking

Long ribs5 (cross-length)

Short ribs11 (cross-width)

Joint typeHalf-depth slot

Est. time30–45 min

Fit the four sidewalls

With the rib lattice in place on the top plate, slide the two long sidewalls (2400mm) into position along each long edge. The sidewall tabs locate into the corresponding slots on the outermost ribs. Follow with the two short end walls (1200mm) at each end.

Use a rubber mallet to fully seat each tab into its slot — panels should locate positively with no play. Do not force panels that feel misaligned; check the rib orientation first.

Note: The sidewalls capture the rib lattice from all four sides. Once all four walls are on, the assembly will be self-supporting and rigid enough to begin clamping.

Both long sidewalls seated and tabbed
Both short end walls seated and tabbed
No gaps between sidewall bottom edge and top plate
Assembly self-supporting — no lean or twist

Long walls2 × 2400 × 150mm

Short walls2 × 1200 × 150mm

Est. time20 min

Clamp the assembly using threaded rod and assembly brackets

Thread the threaded rods (m10) through the pre-cut holes in the sidewalls, passing through the rib lattice. Fit the assembly brackets over the intersecting lattice ribs, and use penny washers at the other end though the table surface. — these bear against the outer face of the sidewalls and distribute clamping load evenly across the panel.

Run nuts up finger-tight on all rods first. Then tighten progressively, working from the centre of each wall outward, clamping in all directions simultaneously. This draws the sidewalls tight against the rib edges and presses the entire lattice firmly against the top plate.

Key: Even clamping pressure across all rods is critical. Do not fully tighten one rod before moving to the next — use multiple passes, incrementally increasing tension on each rod equally.

All threaded rods installed and located
Assembly brackets fitted at all rod ends
Nuts finger-tight on all rods before final tensioning
Clamped progressively centre-out, all directions
No gaps visible between any panels

ClampingThreaded rod + brackets

MethodCentre-out, progressive

Est. time30 min

Check square, then final tighten

Before final tightening, measure corner-to-corner diagonals across the top plate. Both diagonals must match within 2mm. If the assembly is out of square, slacken the rods slightly and apply gentle racking pressure to the longer diagonal corner, then re-tighten.

Once square, bring all rods to final tension in even passes. The assembly is now fully clamped and rigid.

Squareness check: Measure diagonally from corner to corner across the top plate. Both measurements must be equal within 2mm before final tightening.

Diagonal measurements equal within 2mm
All rods at final even tension
No panel movement or flex
Assembly fully rigid in all axes

Diagonal tol.±2mm max

Est. time15 min

Weld the legs, panels and flip upright

The table is still upside-down with the top plate face-down. This is the correct position to start welding. Position each leg mount plate over its corresponding pre-drilled location on the underside of the torsion box. Clamp each leg square using an engineer's square before tacking.

Check all legs are vertical and at equal height before committing to full welds. Once tacked and confirmed, run full fillet welds on all four sides of each leg-to-plate junction. Begin to start welding all the internal faces, remember to distribute the heat as this can cause distootion issues.Allow to cool fully before flipping.

Welding spec: 5mm fillet weld, all four sides of each leg junction. MIG or TIG — ER70S-6 filler or S275 equivalent. Allow full cool before handling.

All 6 legs clamped and tacked square
Leg heights equal — measure from datum plate
Full fillet welds, all 4 sides of each leg
Welds fully cool before flipping upright

Leg section70 × 70 × 3 RHS

Leg qty6

Weld spec5mm fillet, all sides

FillerER70S-6 / S275 equiv.

Est. time45–60 min

Flip upright and level

Once welds are fully cool, flip the table upright onto its legs. Place a spirit level on the top surface and check both axes. The table should sit level to within 1mm across the full 2400mm span.

If adjustment is needed, shim low legs with steel plate shims (not supplied). Do not attempt to level by bending legs — this will stress the welds. Once level, wipe the surface with a light oil to protect the raw steel finish.

Final check: Apply downward pressure to each corner. No rocking should be present. If rocking occurs, identify and shim the low leg until all four corners are solid.

Table upright, all 6 legs on floor
Spirit level within 1mm across 2400mm
No rocking under applied corner load
Surface wiped with light oil

Level tol.1mm / 2400mm

Max load1,500kg distributed

SurfaceRaw oiled steel

Est. time15 min

Section 03

Fixings Specification

Fixings are supplied with the kit — source extras from any fastener supplier (Accu, Fastenright, local trade supplier). All fixings are standard metric.

Location	Fastener	Grade	Qty (Model L)	Torque
Perimeter wall joints	M10 threaded rod	8.8	10	45 Nm
Leg mounting plates	M16 x 40mm bolt	8.8	24	160 Nm
Rib-to-wall connections	M10 threaded rod	8.8	10	45 Nm
Top plate to frame	m10 threaded rod & 30 brackets	8.8	60	45 Nm
All locations	M10 flat washer	—	160 (× 2 per bolt)	—
All locations	M10 nyloc nut	8.8	160 (x2 per rod length)	45 Nm

💡 Order 10% extra fasteners to account for thread damage or assembly errors. Nyloc nuts are single-use — do not reuse once fully tightened.

Section 04

Surface Care & Maintenance

🛢️

After each session

Wipe the surface with a clean rag. Remove spatter with a scraper or wire brush. Apply a thin coat of light machine oil or WD-40 if the table will sit unused for more than a few days.

🔩

Every 3 months

Check all bolts for torque — vibration from heavy fabrication work can cause minor loosening over time. Re-torque to 45 Nm as needed. Inspect welds visually for any cracking.

⚖️

Annually

Re-check surface flatness using a precision straight-edge or laser level. The torsion-box design resists long-term distortion, but heavy point loads over time can cause localised deflection.

Need help?

If you run into any issues during assembly, contact us directly. We're fabricators too — we'll sort it.

Email james@bptables.co.uk Contact page