M40 to M32 Thread Adapter & Gland Reducer — Cut to Your Pitch

Bringing an M40 entry down to an M32 gland — and the stock reducer is too narrow to seal properly against thin cabinet sheet? We machine it with the flange face the hole actually needs, in nickel-plated brass, 316L or steel. From a sketch, no CAD, one piece up. Get a quote →

At M40 the problem moves to the panel

The smaller steps in this family are about the thread and the cable. This size is about the hole and the sheet it is cut in. An M40 entry means a hole of roughly 40.5 mm, and in a typical cabinet that hole is in sheet only 1.5 to 2.5 mm thick.

A 40 mm hole takes most of the local stiffness out of that panel. Pull up the locknut and the sheet dishes — so the sealing washer ends up bearing on a curved surface instead of a flat one, and the IP rating you specified quietly stops being true. A narrow stock reducer concentrates the clamping load right at the hole edge and makes it worse.

What we machine can carry a wider, properly faced flange that spreads the clamping load out onto sound metal and stiffens the hole. It is a small change on the drawing and it is the difference between a joint that seals and one that weeps.

The other reasons this size gets machined

• The pitch is not 1.5 mm on both ends — a mechanical M40×3.0 or M40×2.0 is nowhere in the gland ranges
• One side is PG, not metric — PG 36 to M40 is the pair on older German equipment
• The entry is on a bottom gland plate, where standing water makes the sealing face flatness critical
• The specification calls for 316L and the stock part is brass or nylon
• Bonding and screening continuity matters on a drive or converter cabinet, ruling out plastic
• The stock reducer is too long and fouls a busbar, terminal block or duct behind the plate
• An existing sealing arrangement must be preserved so the IP rating survives the extra joint
• You need a mix of sizes — M40→M32 alongside M32→M25 and M25→M20 — on one order

Pitch & material options

Each end is single-point turned to its own pitch and gauged with a thread ring or plug, so both sides thread on cleanly.

Option	Choices	Notes
M40 end	M40×1.5 (gland standard) · M40×3.0 · M40×2.0 · M40×1.0	Male or female
M32 end	M32×1.5 (gland standard) · M32×2.0 · M32×1.0	Male or female
Instead of M40	PG 36 · PG 42 · 1¼″ NPT · G 1¼	Legacy or imported equipment
Flange face	Standard · wide face for thin sheet	State the panel thickness
Form	Male-female · double-male · female-female	To suit your two parts
Material	Nickel-plated brass · 316L · 304 · steel	Metal-to-metal seat for screening
Drive	Hex to suit · or two spanner flats	Reduced across-flats for crowded plates
Sealing	Flat washer face · O-ring groove · NPT taper	Copied from what seals today

Other size adapters we machine

Three forms we machine

How it's made — and what we need

• Turned from bar — nickel-plated brass, 316L or steel; hex bar where a wrench grip is wanted so the flats come from stock.
• Flange face sized to the panel — tell us the sheet thickness and whether the hole is already cut; we set the face diameter to spread the load onto sound metal.
• Each end cut to its pitch — M40 end and M32 end single-point threaded, chamfered, then gauged.
• Sealing feature machined in — O-ring groove, faced shoulder or taper, copied from what seals on the part today.
• Finished & checked — deburred, edges broken, both threads verified with ring and plug gauges before packing.
• To order it — send a sketch, a photo with a caliper, or the callouts (e.g. "M40×1.5 male → M32×1.5 female, 316L, 2 mm panel, bottom entry"). We draw it, confirm, and quote. How ordering with no CAD works →

Frequently asked

Why does an M40 to M32 reducer need a wider flange face?

Because of the hole it has to cover. An M40 entry is a hole of roughly 40.5 mm cut in sheet only 1.5 to 2.5 mm thick. That takes most of the local stiffness out of the panel, so it dishes when the locknut is pulled up and the seal bears on a curved surface. A machined adapter can carry a wider faced flange that spreads the clamping load and stiffens the hole. If the panel is thick or the entry is in a cast housing, this matters much less.

Which pitches can you cut?

Any combination. The gland default is M40×1.5 to M32×1.5, since all metric gland threads M12–M63 run 1.5 mm under EN 60423. On the mechanical side we also cut M40×3.0, M40×2.0, M40×1.0, M32×2.0 and M32×1.0, plus non-standard pitches on request. Both ends are gauged. More on coarse vs fine pitch →

Can you make it as an M32 to M40 enlarger instead?

Yes — same part, ends swapped. At this size the reducer is usually the common direction: the cabinet was punched for M40 supply entries and the actual cable came in smaller. The M32→M40 enlarger is for the opposite case, a heavier supply cable going into an entry sized for M32.

Can one end be PG instead of metric?

Yes — PG 36 to M40 is the pair at this size. PG 36 measures 47.0 mm with a 1.59 mm pitch on an 80° flank, against metric's 1.5 mm on 60°, so the two cannot be mated directly. We cut PG on one end and metric on the other in one body. Full PG to metric conversion chart →

Where do M40 entries usually turn up?

Main supply entries into distribution and sub-distribution boards, the bottom gland plates of drive and converter cabinets, larger machine control cabinets, and generator and transformer connection boxes. Many of these are bottom entries, so standing water and the flatness of the sealing face matter more than on a side wall.

What's the minimum order, and do you need CAD?

MOQ is one piece, no tooling cost, no CAD needed. A sketch, a photo with a caliper, or the two callouts plus the panel thickness is enough. We draw and confirm before machining, keep the drawing for re-orders, and quote with price breaks at 1, 10, 50 and 200 pieces.