Profile Gage (External) - API Buttress Casing 4-1/2″–13-3/8″ | 5 TPI | 3/4″ TPF

The API Buttress Casing Profile Gage (External) is a precision thread profile inspection tool used to verify API buttress casing thread form on OCTG connections.

Designed for API Spec 5B thread inspection, this gage enables fast visual and dimensional verification of external buttress threads (BTC)—ensuring correct thread geometry, preventing machining defects, and maintaining connection integrity in oilfield applications.

This model covers 4-1/2″ to 13-3/8″ casing sizes, with 5 TPI and 3/4″ taper per foot (TPF), making it a standard tool for casing thread inspection across manufacturing and field operations.

Key Features

• API 5B Thread Profile Verification
  Confirms correct buttress thread geometry for casing connections used in oil & gas operations.

• External Thread Inspection (BTC)
  Specifically designed for external casing threads, ensuring accurate form and pitch validation.

• High-Precision Manufacturing (±0.0002″)
  Produced using EDM technology for tight tolerances and repeatable inspection results. 

• Fast Visual Inspection Tool
  Quickly detects:

  • Chipped inserts

  • Deformed or rolled threads

  • Incorrect tooth profile

  • Worn or stretched threads 

• Standard Oilfield Thread Coverage
  Supports 4-1/2″ to 13-3/8″ API buttress casing threads, widely used in OCTG applications. 

Applications

• OCTG casing inspection (external threads)

• API thread gauging & quality control

• Threading machine setup & verification

• Oil & gas manufacturing QA/QC

• Field inspection & maintenance

Why This Matters

Incorrect thread profile = bad connection performance.

This leads to:

• Improper load distribution

• Poor sealing performance

• Increased risk of connection failure

• Expensive rework and downtime

The ThreadCheck Profile Gage gives you instant pass/fail validation before the connection ever reaches the field.

Technical Specifications

• Product Type: Thread Profile Gage

• Standard: API Spec 5B

• Thread Type: Buttress Casing (BTC)

• Application: External Threads

• Size Range: 4-1/2″ – 13-3/8″

• Threads Per Inch (TPI): 5

• Taper Per Foot (TPF): 3/4″

• Manufacturing Accuracy: ±0.0002″

• SKU: TP-5BTC75-EXT