UNF 2A threads are used for external applications such as bolts and screws, while UNF 2B threads are used for internal applications such as nuts and threaded holes. 2A threads are tighter, while 2B threads have more clearance for easier assembly.

ANSI/ ASME INTERNAL Screw Thread Size Chart. All units are in inches. Unified Screw Threads per. ANSI/ASME B1.1-1989 (R2001), R2001) Nomenclature, are used. Acceptability criteria are described in ANSI/ASME B1.3M-1992 (R2001). Note: This screw chart is not comprehensive of all available standard threads as provided by the standard.

2025年3月10日 · For instance, you might see 2A and 2B screws, which are slightly different sizes. A represents the external threads on the screw shaft and B represents the internal ones.

Classes 2A & 2B: Classes 2A (external) and 2B (internal) are the default classes used for the commercial production of Nut, Bols, and otehr threaded fasteners. They are the default class …

The vast majority of the standards and custom made fasteners are manufactured to a 2A and 2B thread pitch, which allows for the best balance in cost and performance. Tolerances vary for each thread diameter and we are happy to assist you with greater detail for your situation anytime.

0.4170 0.4340 10.5918 11.0236 0.4720 0.4900 11.9888 12.4460 1.螺胚直径指‎滚丝前的尺‎寸，数值为依经‎验公式计算‎而得，在实践中需‎ 验证。 2.标记示例：10-32UNF‎ -2A (或 0.190-32UNF‎ -2A)、3/8-24UNF‎ -2A (或 0.375-24UNF‎ -2A) 2 f美制内螺纹‎ （2B）常用规格极 ‎ 限尺寸表 ...

2016年5月16日 · Unified National Coarse Screw Thread per ANSI B1.1 screw thread date chart. The Nominal Major Diameter and Threads-per-inch (Pitch) are defined by ANSI/ASME B1.1 and are the choices for the customary Unified screws and nuts.

Classes 2A and 2B: These classes are specified for the typical fit grade of commercial products, such as machine screws and fasteners, where interchangeability and reasonable quality and fit predictability is required. These classes are the most commonly used for commercial and aerospace applications.

INTERNAL THREADS – CLASS 2BINTERNAL THREADS – CLASS 2B

ANSI/ASME B1.1 Unified National Thread - UNC Coarse series and UNF Fine series. Unified threads comes in three different classes: UNC threads according ANSI B1.1: Pitch is the …