API Buttress (BUT) Casing Thread Inserts – 16ER / 22ER Series
Ideal for: Oil & Gas Casing, Deep Well Drilling, High Axial Load Joints.
- Product Standard: API Buttress (BUT) Casing laydown threading inserts (API Spec 5B).
- High Performance Profile: Features the asymmetric 3° load flank / 10° stab flank designed to support massive casing string weights.
- Pitch Standard: Dedicated to the standard 5 TPI casing pitch used across varying pipe diameters.
- Taper Options: Precision ground for both 0.75 IPF (3/4″ per foot) and 1.0 IPF (1″ per foot) taper requirements.
- Size Versatility: Stocked in the popular 16er threading insert (3/8″ I.C.) and heavy-duty Size 22 (1/2″ I.C.) formats.
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Machining Flexibility: Premium threading inserts for lathe applications, available in Right-Hand and left hand thread insert configurations.
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Product Overview
Ensure the structural integrity of your oil country tubular goods (OCTG) with our API Buttress (BUT) laydown threading inserts. Designed to meet API Specification 5B, the Buttress thread form utilizes a flat 3° load flank and a 10° stab flank to provide exceptional tensile strength and leak resistance for casing pipes in deep wells.
These carbide threading inserts are engineered to cut the specific 5 TPI pitch on tapered pipes. We offer solutions for both the standard taper (0.75 inches per foot) and the steep taper (1.0 inches per foot) used on larger diameter casings, ensuring precise engagement and seal integrity.
Key Features & Benefits
- High Tensile Strength: The nearly vertical 3° flank transmits heavy axial loads, making it superior to API Round threads for heavy casing strings.
- The 16ER Standard: Our 16er threading inserts (16ER 5 BUT) handle standard casing sizes (4-1/2″ to 13-3/8″), fitting standard ISO tool holders.
- Heavy Duty Capability: For larger casing sizes (16″ to 20″) or enhanced stability, we offer the robust 22ER (Size 22) series.
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Optimized Grade: Tough carbide substrates designed to withstand the heat and abrasion of machining high-grade casing steels (J55, N80, P110).
API Buttress (BUT) Casing Thread Inserts Technical Specifications
| TPI | L | I.C. | Taper | External Model | Internal Model | X | Y | Connection Size |
|---|---|---|---|---|---|---|---|---|
| 5 | 22 | 5/8″ | 0.75 | 22ER5BUT0.75 | 22IR5BUT0.75 | 2.2 | 2.4 | 4 1/2″ ~ 13 3/8″ |
| 5 | 22 | 5/8″ | 1 | 22ER5BUT1.0 | 22IR5BUT1.0 | 2.3 | 2.4 | 16″ ~ 20″ |
| TPI | L | I.C. | Taper | External Model | Internal Model | X | Y | Connection Size |
|---|---|---|---|---|---|---|---|---|
| 5 | 16.5 | 3/8″ | 0.75 | 16ER5BUT0.75 | 16IR5BUT0.75 | 1.3 | 1.5 | 4 1/2″ ~ 13 3/8″ |
| 5 | 16.5 | 3/8″ | 1 | 16ER5BUT1.0 | 16IR5BUT1.0 | 1.3 | 1.5 | 16″ ~ 20″ |
*(Note: Catalog Source 554 lists 22ER models. Please verify specific holder seat size requirements).
Machining Guidelines
- Taper Criticality: API Buttress threads rely on the taper for sealing. Ensure your machine is programmed for 0.75 IPF ($1:16$) or 1.0 IPF ($1:12$) corresponding to the insert and pipe size12.
- Tool Holder: Use standard laydown threading inserts holders. Size 16 inserts fit standard 3/8″ I.C. holders; Size 22 inserts require 1/2″ I.C. holders.
- Insert Orientation: Ensure the 3° load flank is oriented towards the coupling center. Use a left hand thread insert if machining away from the chuck or for special crossovers.
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