ASME/ANSI B16.14 Hexagon Socket Pipe Plugs
ASME/ANSI B16.14 hexagon socket pipe plugs, NPS 1/8–3-1/2 — inch straight pipe-thread plugs seated flush with a hex socket drive, with the collected per-size tables: length L, socket depth k, socket across-flats S and pin-hole n, tabulated in mm and inches.
Last updated: 2026-11
Specifications
The B16.14 hexagon socket pipe plug is the inch-system complement of the DIN 906/908 plug family already paginated in this catalog: a headless cylindrical plug with a hex socket drive that screws into a pipe-thread port and sits flush — the closing plug for gauge ports, drain and vent holes on American-pattern equipment and inch-plumbed manifolds. The collected tables run NPS 1/8 to NPS 3-1/2 in straight pipe-thread designations, and they carry the plug-to-tool geometry in paired millimeter and inch rows exactly as the source prints them: minimum plug length L, minimum socket depth k, socket across-flats S (Basic in fractions, 9/32″ to 1-7/8″) and the pin-hole diameter n — the cross-drilled hole for a locking wire or pin on larger sizes, which the source shows absent ("-") on the three smallest (see the table footnote). As with the DIN plugs, a straight (parallel) pipe thread seals on a gasket, O-ring or sealant at the joint — not on the thread flanks — so the sealing method is specified with the order. Pressure classes, materials and finishes are not tabulated by the collected specification and stay per RFQ.
| Standard | ASME/ANSI B16.14 — hexagon socket pipe plugs (inch series, NPS straight pipe-thread designations as printed) |
|---|---|
| Series | 1/8 NPS – 3-1/2 NPS (four source column groups of three sizes; each value tabulated in millimeters and inches as printed) |
| Tabulated geometry | Per size: L plug length (min, 9.4–30 mm), k socket depth (min, 6.1–21.8 mm), S socket across-flats (Nominal Size, inch fractions 9/32″–1-7/8″), n pin-hole diameter (mm/inch; "-" at 1/8–3/8 NPS — see table footnote) |
| Function | Closes tapped pipe-thread ports flush — gauge, drain and vent ports; straight pipe thread seals on the joint seal, not the flanks |
| Sealing / materials / finish | Not tabulated by the collected specification — per RFQ (state medium, pressure and sealing method: gasket, O-ring or sealant) |
| Attribute | 1/8 NPS | 1/4 NPS | 3/8 NPS |
|---|---|---|---|
| L — min — (mm) | 9.4 | 11.2 | 12.2 |
| (inch) | 0.37 | 0.44 | 0.48 |
| k — min — (mm) | 6.1 | 7.1 | 7.9 |
| (inch) | 0.24 | 0.28 | 0.31 |
| S — Nominal Size — inch | 9/32 | 3/8 | 7/16 |
| n — Nominal Size — (mm) | - | - | - |
| (inch) | - | - | - |
- Row 6 (n — Nominal Size — (mm)): The source prints '-' for the n (pin hole) rows at 1/8-3/8 NPS — the smallest three sizes have no pin hole tabulated.
| Attribute | 1/2 NPS | 3/4 NPS | 1 NPS |
|---|---|---|---|
| L — min — (mm) | 14.2 | 16 | 19.1 |
| (inch) | 0.56 | 0.63 | 0.75 |
| k — min — (mm) | 9.7 | 11.2 | 12.7 |
| (inch) | 0.38 | 0.44 | 0.5 |
| S — Nominal Size — inch | 9/16 | 5/8 | 13/16 |
| n — Nominal Size — (mm) | 4.1 | 4.6 | 5.1 |
| (inch) | 0.16 | 0.18 | 0.2 |
| Attribute | 1-1/4 NPS | 1-1/2 NPS | 2 NPS |
|---|---|---|---|
| L — min — (mm) | 20.3 | 21.1 | 22.4 |
| (inch) | 0.8 | 0.83 | 0.88 |
| k — min — (mm) | 14.2 | 15.8 | 17.3 |
| (inch) | 0.56 | 0.62 | 0.68 |
| S — Nominal Size — inch | 15/16 | 1-1/8 | 1-5/16 |
| n — Nominal Size — (mm) | 5.6 | 6.1 | 6.6 |
| (inch) | 0.22 | 0.24 | 0.26 |
| Attribute | 2-1/2 NPS | 3 NPS | 3-1/2 NPS |
|---|---|---|---|
| L — min — (mm) | 27.2 | 28.7 | 30 |
| (inch) | 1.07 | 1.13 | 1.18 |
| k — min — (mm) | 18.8 | 20.3 | 21.8 |
| (inch) | 0.74 | 0.8 | 0.86 |
| S — Nominal Size — inch | 1-1/2 | 1-11/16 | 1-7/8 |
| n — Nominal Size — (mm) | 7.4 | 7.9 | 8.6 |
| (inch) | 0.29 | 0.31 | 0.34 |
Materials
- Material, finish and sealing method specified per RFQ — state the medium (oil, water, air, refrigerant) and pressure at quotation
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (ASME/ANSI B16.14 Hexagon Socket Pipe Plugs) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
ASME B16.14 or DIN 906/908 — which plug for my port, and how do I order it?
Follow the port's thread system and the drive you want, then order by the exact designation. The collected B16.14 series is the inch answer: NPS designations from 1/8 to 3-1/2, hex socket drive, flush seat — for equipment built to inch practice. The DIN 906 (hex socket, tapered thread) and DIN 908 (hex socket, parallel thread) pages in this catalog are the metric-system answer, and the drive trade-off is the same across both systems: a socket plug sits flush where a hex-head DIN 910 would stand proud. What to state at RFQ is the same everywhere: the exact port designation (the collected tables label columns "1/8 NPS" through "3-1/2 NPS" — quote it verbatim), the sealing method, since straight pipe threads of this kind seal on a gasket, O-ring or sealant and not on the flanks, and the medium and pressure. One reading note from the source: the pin hole n (for wire locking) appears only from 1/2 NPS upward — the three smallest sizes print "-" — so if the specification calls for a locked plug, size applies.
What is the MOQ and lead time for this screw type?
The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common sizes in this screw type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support