The DIN classification of taps is a detailed specification of different types, application scenarios, and structures of taps based on the German Industrial Standard (DIN, Deutsches Institution f ü r Normung). These classifications help users choose the most suitable tap for their machining needs, including thread form, material, length, groove type, manual or machine use, etc. Their detailed descriptions are as following:

1. DIN 2181: Hand and Machine Taps

Standard Name: Hand and Machine Taps

Application: This standard covers both hand taps and machine taps with straight flutes, used for general-purpose threading. They are suitable for cutting metric threads in through holes and blind holes.

Characteristics: These taps are commonly supplied in sets (taper tap, intermediate tap, and bottoming tap) to gradually form the thread. They are versatile, designed for manual operations but can also be used with machines at lower speeds.

2. DIN 352: Straight Flute Taps for Metric Threads

Standard Name: Straight Flute Taps for ISO Metric Threads

Application: This standard describes straight flute taps designed for cutting metric threads. These taps are commonly used in general-purpose applications and are ideal for hand tapping or use in slower-speed machine operations.

Characteristics:

Straight flutes allow chips to remain in the flute during cutting, making them suitable for shallow and through holes.

Typically sold in sets with taper (roughing), intermediate (second), and finishing taps for progressive threading.

3. DIN 371: Short Machine Taps with Reinforced Shank

Standard Name: Short Machine Taps for Metric Threads with Reinforced Shank

Application: These taps are designed for cutting metric threads, primarily in through holes, and are used with machinery, particularly where higher strength is required due to the thicker shank.

Characteristics:

Shorter design with a reinforced (thicker) shank, increasing strength and reducing the risk of breakage, especially in harder materials.

Ideal for smaller diameter threads and automated production environments due to their high rigidity.

4. DIN 374: Long Machine Taps with Reinforced Shank

Standard Name: Long Machine Taps for Metric Threads with Reinforced Shank

Application: Suitable for cutting deeper metric threads in through holes or blind holes.

Characteristics:

Similar to DIN 371 but longer in overall length, allowing for deeper hole threading.

The reinforced shank provides increased durability and is useful in demanding machining applications requiring extra reach or depth.

5. DIN 376: Standard Machine Taps for Metric Threads

Standard Name: Machine Taps for Metric Threads with Normal Shank

Application: Standard machine taps used in various threading operations, including general engineering and machinery manufacturing.

Characteristics:

These taps have a standard length and are used for both through and blind hole threading.

Available in various flute designs, including straight flute and spiral flute configurations, depending on the specific threading application.

6. DIN 5156: Taps for Pipe Threads (BSP)

Standard Name: Taps for Parallel Pipe Threads (BSP)

Application: This standard specifies taps used to cut British Standard Pipe (BSP) threads, typically for fittings, couplings, and piping systems.

Characteristics:

BSP threads are parallel, and these taps are designed to cut precise pipe threads, ensuring leak-free connections in plumbing and hydraulic systems.

7. DIN 5157: Taps for Tapered Pipe Threads (BSPT)

Standard Name: Taps for Tapered Pipe Threads (BSPT)

Application: This standard applies to taps used for cutting British Standard Pipe Tapered (BSPT) threads, common in high-pressure systems requiring leak-proof threaded connections.

Characteristics:

Tapered thread design ensures a tight seal in applications where fluid or gas leak prevention is critical.

8. DIN 2184-1: Spiral Flute Taps for Blind Holes

Standard Name: Spiral Flute Taps for Metric Threads

Application: Spiral flute taps are designed for cutting metric threads in blind holes, where chip evacuation is crucial.

Characteristics:

The spiral flute design pulls chips upwards and out of the hole, reducing the risk of chip clogging at the bottom of blind holes.

These taps are ideal for use in soft, ductile materials and for producing high-quality threads in blind holes.

9. DIN ISO 529: Taps for ISO Metric Threads (Imperial Sizes)

Standard Name: Taps for ISO Metric Threads

Application: This standard covers taps used for cutting ISO metric threads but in imperial (inch-based) sizes.

Characteristics:

This standard is often used when dealing with older machinery or equipment requiring imperial-sized tooling but where metric threads are needed.

10. DIN 352: Left-Hand Taps

Standard Name: Left-Hand Taps for Metric Threads

Application: Designed for cutting left-handed threads, which are used in specific applications where reverse thread motion is necessary to prevent unthreading during operation.

Characteristics:

Left-hand taps are less common but are crucial in applications such as rotating parts, where standard right-hand threads would loosen over time.