JCBC Bolt — Joint Connector Bolt

High Tensile  ·  Black Oxide & Galvanized Finish  ·  Hex Socket Drive  ·  M4 to M10

The JCBC Bolt (Joint Connector Bolt) is a high tensile machine bolt with a flat countersunk head and hex socket (Allen key) drive, used to join two furniture panels at a right angle. The bolt passes through a clearance hole in one panel and threads into a barrel nut (cross dowel) fitted into the adjoining panel, drawing the joint together with a clean, flush finish. It is one of the most widely used connectors in knock-down (KD) and flat-pack furniture assembly. Excel Trading Corporation stocks this in black oxide and galvanized (zinc plated) finish.

Specifications

  • Bullet Icon Type: Joint Connector Bolt (JCBC) / Furniture Connector Bolt
  • Bullet Icon Head: Flat countersunk head — sits flush with the panel surface
  • Bullet Icon Drive: Hex socket (Allen key)
  • Bullet Icon Grade: High Tensile (HT); M4 & M5 supplied in Grade 10.9
  • Bullet Icon Finish: Black oxide & Galvanized (zinc plated)
  • Bullet Icon Thread: Machine screw thread, fully threaded shank
  • Bullet Icon Custom manufacturing available to match your specific material requirement

Applications

  • Bullet Icon Knock-down (KD) and flat-pack furniture assembly
  • Bullet Icon Bed frames, cots and headboard panel joints
  • Bullet Icon Wardrobes, cabinets and modular storage units
  • Bullet Icon Shelving systems and modular office furniture
  • Bullet Icon Custom fabrication requiring a flush, reusable panel joint
JCBC Bolt Joint Connector Bolt Black Oxide and Galvanized

Available In

Black Oxide

Galvanized JCBC Bolt

Galvanized

Available Sizes — JCBC Bolt

Choose a length that fully passes through your panel thickness and engages the mating barrel nut. M4 and M5 are supplied in Grade 10.9; M6, M8 and M10 are supplied in standard High Tensile (HT) grade. Custom lengths can be manufactured on request.

Thread Size Grade Available Lengths (mm)
M4 10.9 6  ·  8  ·  10  ·  12  ·  16  ·  20  ·  25
M5 10.9 10  ·  12  ·  16  ·  20  ·  25  ·  30
M6 HT 10  ·  12  ·  16  ·  20  ·  25  ·  30  ·  35  ·  40  ·  45  ·  50  ·  55  ·  60  ·  65  ·  75  ·  80  ·  90  ·  100  ·  125  ·  150
M8 HT 10  ·  12  ·  16  ·  20  ·  25  ·  30  ·  35  ·  40  ·  45  ·  50  ·  55  ·  60  ·  65  ·  75  ·  80  ·  90  ·  100  ·  125  ·  150  ·  175
M10 HT 20  ·  30  ·  40  ·  50  ·  60  ·  70  ·  80  ·  100

Finish Options

Black Oxide

Matte Black · Low-Glare Finish

A thin black conversion coating that gives a matte black appearance with mild corrosion resistance. The standard choice for visible furniture hardware paired with dark wood, black metal fittings or minimalist furniture designs where a low-glare, understated finish is preferred.

Best for: Dark wood furniture · Black hardware designs · Indoor visible joints

Galvanized (Zinc Plated)

Bright Silver Finish

A bright zinc plated finish offering better corrosion resistance than black oxide, suited to humid environments or furniture with lighter-coloured or silver-toned hardware. The reflective finish also makes fasteners easier to spot during assembly.

Best for: Light wood furniture · Humid environments · Silver hardware designs

Quick Specifications

M4–M10

Size Range

HT / 10.9

Grade

Hex Socket

Drive Type

Black / Zinc

Finishes Available

Installation Tips

  • ▸ Always pair the JCBC bolt with a matching barrel nut — driving it directly into bare wood is not recommended for load-bearing furniture joints.
  • ▸ Select a length that fully engages the barrel nut without bottoming out — too short and the joint won't tighten; too long and the bolt tip can protrude past the barrel nut.
  • ▸ Use the correct size hex key for the socket drive — an undersized key rounds out the socket and makes the bolt difficult to remove later.
  • ▸ Tighten firmly but avoid overtightening into softwood or MDF, which can strip the barrel nut's grip on the panel.

Frequently Asked Questions

What is a JCBC bolt (joint connector bolt)?

A JCBC bolt is a high tensile machine bolt with a flat countersunk head and a hex socket (Allen key) drive, designed to join two furniture panels at a right angle. The bolt passes through a clearance hole in one panel and threads into a barrel nut (cross dowel) fitted into a perpendicular hole in the adjoining panel, drawing the two panels tightly together. It is one of the most common connectors used in knock-down (KD) and flat-pack furniture because the flush head leaves a clean, low-profile finish.

Do I need a barrel nut to use a JCBC bolt, or can it be used alone?

A JCBC bolt is designed to be used together with a barrel nut — the bolt threads into the barrel nut rather than into a tapped hole in wood, which would strip out over repeated assembly and disassembly. Excel Trading Corporation stocks matching barrel nuts alongside the JCBC bolt for exactly this pairing. Using the bolt without a barrel nut into bare wood is not recommended for load-bearing furniture joints.

What is the difference between the black oxide and galvanized finish?

Black oxide is a thin conversion coating that gives a matte black appearance and mild corrosion resistance — the standard choice for visible furniture hardware where a dark, low-glare finish is preferred. Galvanized (zinc plated) gives a bright silver finish with better corrosion resistance for humid environments or lighter-coloured furniture. Choose based on the finish that matches your furniture hardware and the environment it will be used in.

Why are M4 and M5 JCBC bolts a different grade to the larger sizes?

M4 and M5 JCBC bolts are supplied in Grade 10.9, a higher tensile grade than the standard high tensile (HT) specification used for M6, M8 and M10. Smaller diameter bolts have a proportionally smaller cross-section carrying the same type of joint load, so a higher grade steel is used to maintain adequate strength margins at the smaller sizes. All sizes are suitable for standard furniture assembly loads within their rated diameter.

Do you supply JCBC bolts in bulk for furniture manufacturing in Bangalore?

Yes. Excel Trading Corporation stocks JCBC bolts in M4 to M10, black oxide and galvanized finish, at our Kumbarpet store in Bengaluru. We supply furniture manufacturers, carpenters and hardware retailers across Karnataka and India-wide, and can arrange custom manufacturing to match your specific material requirement. Call +91-9448239476 or use the Enquire Now button for availability.