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7/16-28 UNEF Thread Dimensions & Specifications

7/16-28 UNEF Thread Quick Specifications

Schematic of basic thread dimensions for LCA threaded feed‑through EMI filter, illustrates major diameter, pitch, pitch diameter, minor diameter, thread height and 60° thread profile

ParameterSpecification
Thread StandardUnified Thread Standard (UTS)
Thread SeriesUNEF
Nominal Size7/16
Thread Designation7/16-28 UNEF
Threads Per Inch (TPI)28
Major Diameter0.4370 in11.10 mm
Pitch0.0357 in0.907 mm
Pitch Diameter0.4138 in10.511 mm
Minor Diameter0.3945 in10.020 mm
Thread Height0.0193 in0.4900 mm
Addendum0.0116 in0.2950 mm
Thread Angle60°
Common Classes2A / 2B
Typical UsePrecision electronic assemblies

Introduction

The 7/16-28 UNEF thread is one of the most widely used Unified National Extra Fine (UNEF) thread sizes in high-reliability electronic equipment, particularly for thread-mount feedthrough capacitors, EMI filters, RF shielding assemblies, and other precision panel-mounted components.

This page provides a complete engineering reference for 7/16-28 UNEF thread dimensions and specifications, including thread designation, major diameter, pitch, threads per inch (TPI), minor diameter, and tolerance classes.

For engineers selecting threaded mounting solutions for electronic components such as feedthrough filters, EMI filters, RF shielding components, and precision assemblies, understanding the 7/16-28 UNEF specification helps ensure proper mechanical compatibility, reliable installation, and long-term performance.

Quick Answer: The 7/16-28 UNEF thread is one of the most widely used Unified National Extra Fine (UNEF) thread sizes in high-reliability electronic equipment, particularly for thread-mount feedthrough capacitors, EMI filters, RF shielding assemblies, and other precision panel-mounted components.

A 7/16-28 UNEF thread is a Unified National Extra Fine (UNEF) screw thread defined by the Unified Thread Standard (UTS).

The designation means:

  • 7/16indicates the nominal major diameter
  • 28indicates 28 threads per inch (TPI)
  • UNEFindicates Unified National Extra Fine thread series

7/16-28 UNEF Thread Tolerance Classes

Thread tolerance determines how tightly two mating components fit together.

The Unified Thread Standard defines several tolerance classes.

LCA threaded feed‑through filter thread classes diagram, illustrating external thread tolerance classes 2A, 3A and internal thread tolerance classes 2B, 3B for EMI feed‑through capacitor

Class 2A / 2B Threads

Class 2 is the most commonly used commercial tolerance.

External Thread: 7/16-28 UNEF-2A

Internal Thread: 7/16-28 UNEF-2B

Advantages:

  • Good interchangeability
  • Reliable assembly
  • Suitable for mass production
  • Lower manufacturing cost

Typical applications:

  • EMI filter mounting
  • Feedthrough capacitor installation
  • Industrial electronic equipment
  • General instrumentation

Most commercial fasteners use Class 2.

Class 3A / 3B Threads

Class 3 provides a tighter fit.

External Thread: 7/16-28 UNEF-3A

Internal Thread: 7/16-28 UNEF-3B

They are typically selected when requirements include:

  • Higher positional accuracy
  • Reduced movement between mating parts
  • Precision adjustment
  • Aerospace or military specifications

However, tighter tolerances also mean:

  • Higher machining requirements
  • More expensive inspection
  • Greater sensitivity to contamination

7/16-28 UNEF vs Similar Thread Sizes

Engineers often need to determine whether another thread specification can replace 7/16-28 UNEF.

7/16-28 UNEF vs M11 × 1

Parameter7/16-28 UNEFM11 × 1
StandardUnifiedMetric ISO
Major Diameter11.10 mm11.00 mm
Pitch0.907 mm1.000 mm
Pitch Diameter10.511 mm10.35 mm
Minor Diameter10.020 mm9.917 mm
Thread Height0.4900 mm0.541 mm
Thread Angle60°60°

Frequently Asked Questions (FAQ)

Q1. What is the difference between UNF and UNEF?

The difference is thread pitch. UNEF has more threads per inch than UNF. UNEF is typically used where precision and compact mounting are required.

Q2. What tolerance class is commonly used for 7/16-28 UNEF?

The most common tolerance class is:

  • External thread: 7/16-28 UNEF-2A
  • Internal thread: 7/16-28 UNEF-2B

Class 3A/3B is used when tighter precision is required.

Q3. Is 7/16-28 UNEF suitable for EMI filters?

Yes. It is commonly used in:

  • Feedthrough capacitors
  • Thread mount EMI filters
  • RF shielding components
  • Panel-mounted electronic assemblies

Its fine pitch allows compact installation and reliable mechanical retention.

Engineering Support CTA: Selecting a threaded EMI filter or feedthrough capacitor? Share the thread standard and size, panel thickness, voltage/current, capacitance, and environmental requirements with LCA engineers. View Thread Mount Feedthrough Filters

Related Engineering Resources

Thread Standards

Thread Specifications

Thread Guide

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