We can customize nominal diameters from 0.8 mm to 300 mm in metric (M), American (UN, UNC, UNF, UNEF, UNS, NPSC, NPSM, NPSH, NPSF, NPSI, NPSL, NH), British (BSW, BSF), Japanese standard PT, and German standard RP (DIN 2999). We also offer G-tube thread gauges, square thread gauges (Rectangle), R-thread gauges (Rd DIN 405), serrated and trapezoidal threads (Tr, ACME, STUB ACME), and gas cylinder threads (PZ, W). In addition, we provide taper threads (NPT, NPTF, Z, BKG, R, RB, Rc, RP, PT, ZG, WKG, BSPT, ANPT, PTF, etc.), pipe thread gauges (G, PF, PS, BSP, BSPP, etc.), gauges for sewing machines (SM), ST wire thread gauges, bicycle (battery car) special thread gauges (B, BC), electrical appliance thread gauges (1BA, 2BA, 3BA, 4BA, 5BA, etc.), valve thread gauges (5V1, 8V1, etc.), and 80° thread gauges (Pg7, Pg9, Pg11, Pg13.5, Pg16, Pg21, Pg29, Pg36, Pg42, Pg48). We also support API standard gauges, API oil pipe thread gauges, API taper gauges, sucker rod thread gauges (CYG13-10, CYG16-10, CYG19-10, CYG22-10, CYG25-10, CYG29-10, KGG32-10, KGG36-10, KGG40-10), as well as oil pipe thread gauges (LP, TBG, UP TBG, CSG, LCSG, NC).

Precision Measurement Definition and Core Functions of Thread Plug Gauges

STORAEN’s thread plug gauges are essential metrology tools for verifying the dimensional accuracy of internal screw threads, ensuring compliance with international standards and reliable mechanical performance. As a critical thread measuring gauge, our solutions deliver precision through a dual-function Go/No-Go design, covering diverse thread types—from metric and inch-based profiles to specialized BSP thread gauges and BSPP thread gauges for pipe systems.

Defining Precision in Thread Inspection

A thread plug gauge is a binary verification tool. The “Go” end must pass through the internal thread smoothly, confirming that it meets the minimum material condition (nominal size minus the allowable tolerance). Conversely, the “No-Go” end should not enter, ensuring the thread does not exceed the maximum allowable tolerance. This design eliminates subjective interpretation and provides objective results for critical parameters such as pitch diameter, thread angle (typical reference values: 60° for metric and 55° for BSP), and pitch. STORAEN’s gauges follow recognized thread plug gauge standard references including ISO 965-3, ASME B1.2, and DIN 13, supporting traceable accuracy across industries.

Core Functions for Diverse Applications

Comprehensive Thread Type Coverage

Our screw thread gauges support a wide range of thread profiles:

Metric Threads (M Series): Suitable for general industrial applications, with precision grades up to 6H for tight-tolerance applications such as automotive engine components.
BSPP (Parallel) & BSPT (Tapered) Threads: Designed for leak-proof pipe connections in hydraulic systems (BSPP) and gas pipelines (BSPT), supporting ISO 7-1 and BS EN 10226 requirements.
NPT Threads: Custom solutions for conical pipe threads per ASME B1.20.1, critical for pressure integrity in the oil and gas sector.

Efficiency in Quality Control

The user-friendly Go/No-Go mechanism can reduce inspection time by up to 50% compared with manual measurement methods, making it ideal for high-volume production lines. By immediately identifying non-conforming threads, our thread gauge tool helps minimize rework costs and prevents defective components from moving into assembly. This is particularly important in aerospace fastener manufacturing or medical device production, where thread failure risks are critical.

Material and Design Durability

Constructed from high-carbon tool steel (hardened to 60HRC+) or tungsten carbide, STORAEN’s thread plug gauges resist wear and maintain dimensional stability in high-temperature or abrasive environments. The surface finish (typical reference: Ra ≤ 0.05 µm) supports smooth insertion, helping protect both the gauge and the workpiece during repeated use.

Trust STORAEN for Critical Thread Assurance

Whether you are calibrating internal threads in automotive transmissions, verifying BSPP connections in industrial hydraulics, or ensuring NPT thread compliance for energy infrastructure, STORAEN’s thread plug gauges provide dependable precision and reliability. By combining strict adherence to thread plug gauge standards with versatile designs for global thread types, we enable manufacturers to achieve zero-defect production—one thread at a time.

Technical Specifications and Manufacturing Processes of Thread Plug Gauges

STORAEN’s thread plug gauges are precision-engineered metrology tools designed to meet the demanding requirements of internal thread inspection. They combine detailed technical specifications with rigorous manufacturing processes to ensure accuracy, durability, and compliance with global standards. As a trusted provider of screw thread gauges and BSP thread gauges, we deliver solutions that set a benchmark for excellence in thread measurement across industries from automotive to aerospace.

Technical Specifications: Precision Defined for Every Application

Size & Thread Type Coverage

Our thread plug gauges cover a nominal diameter range from 0.8 mm (M1) for micro-precision components to 300 mm (M300) for heavy industrial threads, accommodating diverse profiles:

Metric Threads (ISO): Grades 4H to 8H, suitable for general engineering (e.g., M20×1.5-6H);
BSPP & BSPT Threads: Parallel (BSPP, ISO 7-1) and tapered (BSPT, BS EN 10226) variants for leak-proof pipe connections, including sizes such as G1/2 and R1/4;
Specialized Types: Custom solutions for NPT, ACME, and proprietary threads, supporting compatibility with thread plug gauge standard references such as ASME B1.2 and DIN 13.

Accuracy & Tolerance Control

Available in precision classes h6 to h9 (with h6 as the highest grade), our gauges achieve micron-level accuracy (e.g., ±0.0015 mm for M10×1.0). Each thread measuring gauge is calibrated against traceable standards and is accompanied by documentation linking to national metrology institutes (e.g., NIST, PTB), supporting compliance with ISO 9001 quality systems.

Material & Surface Finish

Constructed from high-carbon tool steel (hardened to 60HRC+) or tungsten carbide for high wear resistance, our thread gauge tool features a mirror-like surface finish (typical reference: Ra 0.05 µm) to minimize friction during insertion. Optional TiN coatings improve corrosion resistance in harsh environments and extend service life (typical reference: by 25%).

Manufacturing Processes: Craftsmanship in Every Step

Computer-Aided Design (CAD)

The process begins with 3D modeling of thread parameters—pitch, flank angle, and tolerance zones—using advanced software to ensure alignment with customer specifications and thread plug gauge standard requirements. Specialized modules support complex profiles such as BSPP thread gauges, enabling accurate replication of thread angles (typical reference: 55°) and parallel flank designs.

Precision Machining

Raw materials undergo heat treatment to optimize hardness before CNC grinding and honing to shape the thread profile with micron-level accuracy. For complex geometries, wire EDM (electrical discharge machining) is used to form sharp, burr-free thread roots—critical for preventing measurement errors in tight-tolerance applications.

Superfinishing & Calibration

A rigorous superfinishing process polishes the gauge surface to the specified Ra finish, followed by multi-point calibration using coordinate measuring machines (CMMs) and optical interferometers. This ensures that both the “Go” and “No-Go” ends meet their respective tolerance limits as defined by international standards.

Quality Assurance & Certification

Each thread plug gauge undergoes 100% functional testing to verify Go/No-Go performance, with results documented in a traceable report. This quality commitment makes our gauges a preferred choice for industries where thread integrity is non-negotiable, such as aerospace fasteners and medical device manufacturing.

Trust STORAEN for Uncompromising Precision

Whether you require a standard thread plug gauge for metric threads, a specialized BSP thread gauge for pipe systems, or a custom solution for proprietary profiles, STORAEN’s technical specifications and manufacturing expertise deliver consistent reliability. By integrating global standards with innovative engineering, we ensure that each thread gauge tool we produce sets a benchmark for precision—supporting your quality control processes with confidence.