ANSI/ASME B18.15 Lifting Eye Bolts (Shoulder Type)
ANSI/ASME B18.15 shoulder-type lifting eye bolts, nominal 1/4″–1-3/4″ — machinery eye bolts with a turned shoulder that seats to carry angled lifts, with the collected per-size tables: d s, Type A/B shoulder lengths L 1, eye d 1, d k, hole d 0, overall L, thread b and k.
Last updated: 2026-11
Specifications
The shoulder-type machinery eye bolt is the rigging point you thread into a tapped hole: the collar (shoulder) under the ring seats flush against the mounting surface, and that seat is what lets the eye take loads at an angle — a plain eye bolt without a shoulder is derated drastically off-vertical, while a properly seated shoulder pattern keeps most of its capacity to 45° per the rigging practice the standard serves. ANSI/ASME B18.15 is its inch-series home. The collected tables run nominal 1/4″ to 1-3/4″, and they expose the series' structure honestly: each nominal diameter appears in two column groups with different shoulder diameters d s and different Type A / Type B shoulder lengths L 1 and thread lengths b — two executions of the same nominal size, not legended on the collected page (see the table footnote), which is exactly the detail to confirm against the tapped hole before ordering. Per size the tables carry shoulder length L 1 (Type A/B), eye outside diameter d 1, eye thickness d k, hole diameter d 0, overall length L, thread length b (Type A/B) and eye section k. Working loads are not tabulated by the collected specification — rigging capacities come from the manufacturer's rated load chart and stay per RFQ.
| Standard | ANSI/ASME B18.15 — lifting eye bolts, shoulder type (machinery eye bolts, inch series) |
|---|---|
| Series | Nominal 1/4″ – 1-3/4″ (ten source column groups; each nominal appears in two groups with differing d s / L 1 / b — see table footnote) |
| Tabulated geometry | Per column: d s shoulder diameter; L 1 shoulder length (Type A / Type B); d 1 eye outside diameter; d k eye thickness; d 0 hole diameter; L overall length; b thread length (Type A / Type B); k eye section height |
| Rigging duty | Shoulder seats against the mounting face to support angled lifts; capacity is a rated-load matter — not tabulated by the collected specification, per RFQ (state intended sling angle and proof-test requirements) |
| Materials | Not tabulated by the collected specification — per RFQ (forged carbon steel is the norm; state finish and certification) |
| Attribute | 1/4 | 1/4 | 5/16 |
|---|---|---|---|
| d s | 0.25 | 0.28 | 0.31 |
| L 1 — Type A | 1 | 1.06 | 1.12 |
| Type B | 1 | 1.06 | 1.06 |
| d 1 | 0.69 | 0.81 | 0.81 |
| d k | 1.19 | 1.19 | 1.44 |
| d 0 | 0.19 | 0.25 | 0.25 |
| L | 2.22 | 2.53 | 2.66 |
| b — Type A | 0.75 | 0.75 | 0.81 |
| Type B | 0.75 | 0.75 | 0.75 |
| k | 0.12 | 0.19 | 0.12 |
- Row 1 (d s): The source tabulates two column groups per nominal diameter (1/4, 1/4, 5/16 …) with different d s values and different Type A/B L 1 and b — the split is not legended on the collected page; quote the exact d s when ordering.
| Attribute | 5/16 | 3/8 | 3/8 |
|---|---|---|---|
| d s | 0.34 | 0.38 | 0.41 |
| L 1 — Type A | 1.19 | 1.25 | 1.38 |
| Type B | 1.13 | 1.12 | 1.25 |
| d 1 | 0.94 | 0.94 | 1.06 |
| d k | 1.44 | 1.69 | 1.69 |
| d 0 | 0.31 | 0.31 | 0.38 |
| L | 2.97 | 3.09 | 3.47 |
| b — Type A | 0.81 | 0.88 | 0.88 |
| Type B | 0.75 | 0.75 | 0.75 |
| k | 0.19 | 0.12 | 0.19 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 7/16 | 7/16 | 1/2 |
|---|---|---|---|
| d s | 0.44 | 0.47 | 0.5 |
| L 1 — Type A | 1.38 | 1.5 | 1.5 |
| Type B | 1.13 | 1.25 | 1.13 |
| d 1 | 1 | 1.12 | 1.12 |
| d k | 1.81 | 1.81 | 2.12 |
| d 0 | 0.34 | 0.41 | 0.44 |
| L | 3.41 | 3.78 | 3.81 |
| b — Type A | 1 | 1 | 1.12 |
| Type B | 0.75 | 0.75 | 0.75 |
| k | 0.19 | 0.25 | 0.19 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 1/2 | 9/16 | 9/16 |
|---|---|---|---|
| d s | 0.53 | 0.56 | 0.59 |
| L 1 — Type A | 1.62 | 1.62 | 1.75 |
| Type B | 1.25 | 1.21 | 1.34 |
| d 1 | 1.25 | 1.19 | 1.31 |
| d k | 2.12 | 2.25 | 2.25 |
| d 0 | 0.5 | 0.47 | 0.53 |
| L | 4.19 | 4.19 | 4.56 |
| b — Type A | 1.12 | 1.25 | 1.25 |
| Type B | 0.75 | 0.84 | 0.84 |
| k | 0.25 | 0.22 | 0.28 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 5/8 | 5/8 | 3/4 |
|---|---|---|---|
| d s | 0.62 | 0.66 | 0.75 |
| L 1 — Type A | 1.75 | 1.88 | 2 |
| Type B | 1.31 | 1.44 | 1.5 |
| d 1 | 1.31 | 1.44 | 1.44 |
| d k | 2.56 | 2.56 | 2.81 |
| d 0 | 0.56 | 0.62 | 0.62 |
| L | 4.56 | 4.94 | 5.06 |
| b — Type A | 1.38 | 1.38 | 1.62 |
| Type B | 0.94 | 0.94 | 1.12 |
| k | 0.25 | 0.31 | 0.25 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 3/4 | 7/8 | 7/8 |
|---|---|---|---|
| d s | 0.78 | 0.88 | 0.91 |
| L 1 — Type A | 2.12 | 2.25 | 2.38 |
| Type B | 1.62 | 1.75 | 1.88 |
| d 1 | 1.56 | 1.56 | 1.69 |
| d k | 2.81 | 3.19 | 3.19 |
| d 0 | 0.69 | 0.75 | 0.81 |
| L | 5.5 | 5.75 | 6.19 |
| b — Type A | 1.62 | 1.81 | 1.81 |
| Type B | 1.12 | 1.31 | 1.31 |
| k | 0.31 | 0.31 | 0.38 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 1 | 1 | 1-1/8 |
|---|---|---|---|
| d s | 1 | 1.06 | 1.12 |
| L 1 — Type A | 2.5 | 2.62 | 2.75 |
| Type B | 1.94 | 2.06 | 2.13 |
| d 1 | 1.69 | 1.81 | 1.94 |
| d k | 3.56 | 3.56 | 4.06 |
| d 0 | 0.88 | 0.94 | 1 |
| L | 6.44 | 6.88 | 7.31 |
| b — Type A | 2.08 | 2.08 | 2.31 |
| Type B | 1.5 | 1.5 | 1.69 |
| k | 0.38 | 0.44 | 0.44 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 1-1/8 | 1-1/4 | 1-1/4 |
|---|---|---|---|
| d s | 1.19 | 1.25 | 1.34 |
| L 1 — Type A | 2.88 | 3 | 3.12 |
| Type B | 2.26 | 2.38 | 2.5 |
| d 1 | 2.06 | 2.12 | 2.25 |
| d k | 4.06 | 4.44 | 4.44 |
| d 0 | 1.06 | 1.09 | 1.16 |
| L | 7.75 | 8 | 8.44 |
| b — Type A | 2.31 | 2.5 | 2.5 |
| Type B | 1.69 | 1.88 | 1.88 |
| k | 0.5 | 0.5 | 0.56 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 1-1/2 | 1-1/2 | 1-3/4 |
|---|---|---|---|
| d s | 1.5 | 1.59 | 1.75 |
| L 1 — Type A | 3.5 | 3.62 | 3.75 |
| Type B | 2.75 | 2.87 | 3.18 |
| d 1 | 2.44 | 2.56 | 2.75 |
| d k | 5.19 | 5.19 | 6 |
| d 0 | 1.31 | 1.38 | 1.5 |
| L | 9.22 | 9.72 | 10.5 |
| b — Type A | 3 | 3 | 3.19 |
| Type B | 2.25 | 2.25 | 2.62 |
| k | 0.5 | 0.62 | 0.5 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
| Attribute | 1-3/4 | 2 | 2 |
|---|---|---|---|
| d s | 1.84 | 2 | 2.09 |
| L 1 — Type A | 3.88 | 4 | 4.12 |
| Type B | 3.31 | 3.62 | 3.79 |
| d 1 | 3 | 3.06 | 3.44 |
| d k | 6 | 6.88 | 6.88 |
| d 0 | 1.62 | 1.75 | 1.88 |
| L | 11.12 | 11.53 | 12.22 |
| b — Type A | 3.19 | 3.38 | 3.38 |
| Type B | 2.62 | 3 | 3 |
| k | 0.62 | 0.62 | 0.75 |
- Row 1 (d s): The source repeats each nominal diameter (two column groups per size with differing d s and L 1/b values) with no legend for the split — kept verbatim; quote the exact d s when ordering.
Materials
- Material, finish and rated load specified per RFQ — lifting hardware ships with the manufacturer's rated-load documentation; confirm sling angle and testing 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 (ANSI/ASME B18.15 Lifting Eye Bolts (Shoulder Type)) 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 1,000–10,000 pieces depending on size. Stock items run 3–7 days. High-strength and custom parts run 15–25 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
What must be true before a shoulder eye bolt takes an angled load?
Three things, and the geometry in the collected tables is only the first. First, the seat: the shoulder must bear fully on a flat, machined surface — the L 1 shoulder lengths (Type A/B, 0.75″–3.75″ in the collected tables) exist so the collar reaches a properly prepared seat; on a rough or curved face the shoulder cannot seat and the bolt must not be angle-loaded. Second, the thread engagement: the collected tables print thread lengths b per type — the tapped hole must take the full b (and the two column groups per nominal size differ here; see the table footnote and match the exact d s to your hole). Third, the load rating: the collected specification tabulates geometry only, so the working load for the planned sling angle comes from the manufacturer's rated-load chart, reduced per rigging practice for the angle, with side-loading avoided or specially rated. When ordering, state nominal size with the shoulder diameter, the tapped hole, the finish, and whether proof certificates are required — lifting points are confirmed hardware, not commodity bolts.
What is the MOQ and lead time for this bolt type?
The minimum order quantity is 1,000–10,000 pieces depending on size. Stock items ship in 3–7 days; high-strength and custom parts in 15–25 days. Common sizes in this bolt type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
Related knowledge
- What Bolt Property Classes 8.8, 10.9 and 12.9 Encode — and When High Strength Stops Being the Right Choice
- Bolt Grade Selection: ISO 898-1 8.8/10.9/12.9 vs ASTM A307 and A325
- 8.8 vs 10.9 vs 12.9 Bolts: Strength, Hardness and Cost — What the Evidence Settles
- Calculating Bolt Preload and Clamp Force: Torque, Friction and Tightening Method
- How to Determine Tightening Torque and Choose a Tightening Method for a Bolted Joint
- Fastener Failure Modes: Which Fatigue, Creep and SCC Controls the Evidence Supports
- Hydrogen Embrittlement in High-Strength Bolts: Which Grades Need Controls, Which Coatings and Baking Schedules Are Acceptable, and What to Require Before the RFQ
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