Table of Contents

## What is the minor diameter of a thread?

Minor Diameter: The smallest diameter of the thread of the screw or nut. The term “minor diameter” replaces the term “core diameter” as applied to the thread of a screw and also the term “inside diameter” as applied to the thread of a nut.

**What is the tolerance of thread?**

The tolerance position is the distance of the tolerance from the basic size of the thread profile. For nut threads there are two tolerance positions, H with a zero fundamental deviation (distance of the tolerance position from the basic size) and G with a positive fundamental deviation.

**Which of the following is not correct when minor and major diameter have errors?**

6. Which of the following is not correct when minor and major diameter have errors? Explanation: Errors on the minor and major diameters will cause interference in the mating thread.

### How is the minor diameter of external thread checked generally?

Here’s another way to measure the minor diameter on an external thread. First, measure the major diameter at some location. Then, using a “Pit Depth Gage” of sufficient depth, measure from the major diameter to the thread root. Measure both sides, and substract.

**Is standard for thread tolerance?**

The International Organization for Standardization (ISO) set the standard for limits of metric screw thread. ISO 965 specifies the basic profile for ISO general purpose metric screw threads (M) conforming to ISO 261. The information below can be used to calculate the values of thread tolerances defined by ISO 965/1.

**What is tolerance class for metric threads?**

The tolerance system for metric threads is composed of a two sets of a number followed by a letter. The first set indicates the pitch diameter tolerance, and the second set indicates the major diameter tolerance. Numbers indicate the range of tolerance or tolerance grade.

#### What is the major diameter of a #12 screw?

Basic Dimensions for Coarse Thread Series Parts (UNC/UNRC) | ||
---|---|---|

(measured in inches) | ||

#8 | 0.164 | 0.130 |

#10 | 0.190 | 0.145 |

#12 | 0.216 | 0.171 |

**Which of the following ways is the simplest to measure the minor diameter of a screw thread?**

The best way of measuring a minor diameter is to measure it using a floating carriage micrometer described in Chapter 4. The carriage has a micrometer with a fixed spindle on one side and a movable spindle with a micrometer on the other side.

**What is the effect of pitch error co4?**

1. What is the effect of pitch error? Explanation: An error in pitch increases the effective diameter of a screw or bolts virtually and virtually decreases the effective diameter of a nut.

## What is the formula for pitch?

Pitch = tan (angle), where angle is pitch of roof expressed in degree. degrees to roof pitch = tan (angle) × 12, this will give you X in the ratio X/12.

**What is the major diameter tolerance of effective diameter for external threads?**

+0.01√p

7. What is the major diameter tolerance of effective diameter for external threads? Explanation: In major diameter, the tolerance is given by expression Effective Diameter tolerance = +0.01√p. It is applicable for all grades of fits for external threads.

**How is thread clearance calculated?**

Measure the actual minor diameter and divide by 2 to get half the actual minor 2. Look up or calculate (Nominal Major – 1.08253 x Pitch) the basic minor and divide by 2 to get half the basic minor 3. Add half the actual minor and half the basic minor together 4.

### What does 6H tolerance mean?

A class of thread fit roughly equivalent to 2A/2B is “6g/6H”, which means an external thread with tolerance grade of 6 and position g, and an internal thread of tolerance class 6 with position H. “4h6h/4H5H” is a class of thread fit used for some aerospace fasteners, and is roughly equivalent to 3A/3B.

**What is the OD of a number 12 screw?**

The diameters listed in the chart below are in fractions of an inch, so the #12 is just shy of 1/4 inch.

**What is the thread tolerance of a screw?**

For more information on measuring thread diameters and pitch diameters, please see our article on How To Measure Screws. As an example, a common screw thread tolerance is 5g6g, which indicates a 5g tolerance on its pitch diameter, and a 6g tolerance on its external (thread) diameter.

#### What is the difference between pitch diameter tolerance and minor diameter tolerance?

In internal thread tolerance class designation, the pitch diameter tolerance is followed by minor diameter tolerance. If the two class designations for the pitch diameter and minor diameter are same, it is not necessary to repeat the symbols. (Ex: M6 x 1 – 6H)

**What is the ASME standard for internal thread dimensions?**

Metric internal thread dimensions chart according to ASME B1.13M “Metric Screw Threads: M Profile” standard. Minor diameter, pitch diameter and major diameter are given dimensions in the internal thread chart. All dimensions are in millimeters.

**What is the maximum size of a screw thread?**

CONTACT US Sizes Screw Thread Limits Table Screw Size Class Thread Major Diameter Pitch Diameter Minor Diameter Basic Max. Min. Basic Max. Min. Max. 0-80