High Performance Taps are designed and manufactured for successful threading in a variety of part materials for high and low volume applications. These materials include aluminum, stainless steels, nickel alloys, titanium alloys, mold steels, irons, brass, bronze and plastics. Special geometries, tap surface treatments and premium steels interact to offer the highest level of performance.
High performance tap geometries create less torque during tapping allowing for better removal of chips so the tool can run cooler. Computer Numerical Control (CNC) necked design taps increase the flow of coolant to the cutting teeth and reduce surface contact between the tool and the workpiece for more efficient threading.
Diagram of a High Performance Tap
Flutes:
High performance taps typically have several flutes constructed in their design. They are the grooves or valleys cut into the body of the tap. Higher numbers of flutes increase the strength of the tap and reduce space or chip flow.
Thread size is the number of Threads per Inch (TPI) which is measured along the length of the tap. Metric sizes are referred to as thread pitch.
Chamfers are the length of the tapering threads at the front of the tap. Both the chamfered portion of the tap and the first full thread beyond the chamfer produce the finished thread of the part.
Types of High Performance Taps:
Spiral point taps are used for tapping through holes. They have a flute geometry that shoots chips ahead of the cutting action to reduce loading and clogging within the flute.
Spiral flute taps are used for threading blind holes in aluminum, brass and softer steels. The flute geometry draws the chips away from the hole where chip disposal may be an issue.
Thread forming taps do not cut threads; rather, they form threads by displacing material. They generate threads without producing chips. They are used on mild steels, carbon steels and low to medium alloys.
Class of Fit is the standard identification system describing the tolerance and closeness of fit between the threaded hole and the tap. Unified threads are defined with an A (external) or B (internal). Metric H (internal) or G (external).
Example Applications:
- Class 1A & 1B - For frequent quick assembly, loose assembly
- Class 2A & 2B - Fit is medium loose to eliminate seizure in assembly. Used for screws, bolts and nuts
- Class 3A & 3B - Accuracy of thread is required; gages are used to ensure a tight fit
Thread Limit is a standard notation system indicating a level of tolerance for the thread outside the basic thread size of the tap. The limits are identified by a letter "H" for inch or a "D" for metric, followed by a number. Thread limits have been established to provide a choice in the selection of the tap size best suited to produce the class of thread desired.
The difference in size from one H limit to the next is .0005″ increments for taps through 1″ diameter. Sizes over 1″ diameter are separated by .001″ diameter increments. If the threads in the part are too loose, smaller numbers such as H1 or H2 are used. If the threads are too tight, the H limit number is increased. Proper selection of the H limit number ensures that the threads are within the tolerance required by the part print. Best rule of thumb: always select the largest "H" limit possible to achieve proper class of fit and maximum tool life.
Thread Limit (H & D) Cross Reference Guide | |
|---|---|
| H1 /D1 | Basic plus .0005" - .0010" |
| H2 /D2 | Basic plus .0005" - .0010" |
| H3 /D3 | Basic plus .0010" - .0015" |
| H4 /D4 | Basic plus .0015" - .0020" |
| H5 /D5 | Basic plus .0020" - .0025" |
| H6 /D6 | Basic plus .0025" - .0030" |
| H7/D7 | Basic plus .0030" - .0035" |
| H8/D8 | Basic plus .0035" - .0040" |
| H9/D9 | Basic plus .0040" - .0045" |
| H10/D10 | Basic plus .0045" - .0050" |
| H11/D11 | Basic plus .0050" - .0055" |
| H12/D12 | Basic plus .0055" - .0060" |
Chamfer refers to the length of the tapering threads at the front of the tap. Both the chamfered portion of the tap and the first full thread beyond the chamfer produce the finished thread of the part.
Bottoming chamfers are used for threading blind holes to the bottom. They have 1 to 2 chamfer threads.
Modified Bottoming chamfers are similar to bottoming chamfers, but they are longer and have more teeth. They are used for threading to the bottom of blind holes and have 2 to 2-1/2 chamfer threads.
Taper chamfers, also known as starter taps, have a longer chamfer and require a less aggressive cutting action. They have 7 to 10 chamfer threads.
Plug chamfers are the most commonly used chamfer and are designed for efficiently threading through and blind holes. They have 3 to 5 chamfer threads.
Semi-Bottoming chamfers are used for blind holes. They have 3 to 3-1/2 chamfer threads.
Spiral Point Plugs chamfers are used for general purpose applications. They are 4 to 5 chamfer threads
Bright provides a smooth, polished finish on the tool. It increases chip flow in softer materials such as aluminum, wood and plastic.
Titanium Nitride (TiN) is a multi-purpose coating which increases chip flow in softer materials. The heat and hardness resistance allows the tool to run at higher speeds than uncoated tools.
Titanium Carbonitride (TiCN) is harder and more wear resistant than TiN. It is used on stainless steels, cast iron and aluminum alloys.
Oxide, also known as black oxide or steam oxide, is a surface treatment that prevents chip building, galling and welding on the workpiece. It is commonly used on low carbons, stainless steel and ferrous metals.
Chrome Plate is a bright electroplated coating that offers excellent anti-friction properties. It is commonly used on steel, aluminum, brass, copper or other nonchromium materials
Nitride is a thin, hard-shell coating that supports surface hardness of the tool. It is used where abrasive or wearing conditions exist.
Aluminum Chromium Nitride (AlCrN) has higher-heat resistance than AlTiN. It is commonly used for machining aircraft and aerospace materials, nickel alloys, stainless steel, titanium, cast iron and carbon steel.
Aluminum Chromium Titanium Nitride (AlCrTiN) is a high heat and wear resistant multilayered PVD coating. It is designed for enhanced tool life and superior thread finish.
TiCN PLUS Titanium Carbon-Nitride (TiCN) plus Titanium Nitride (TiN) is an all-purpose finish designed to increase tool life by two to four times more than TiN coated tools. The heat and hardness resistance allows the tool to run at higher speeds than uncoated tools.
Uncoated tools do not feature supportive treatments on the cutting edge. They are used at reduced speeds in general applications on nonferrous metals.
Cobalt is harder than high speed steel and provides better wear resistance. It is commonly used on high tensile alloys.
High Speed Steel (HSS) provides good wear resistance and can be used in general purpose applications for both ferrous and nonferrous materials.
Solid Carbide provides better rigidity than high speed steel. It is extremely heat resistant and used for high speed applications on cast iron, nonferrous materials, plastics and other tough-to-machine materials.
Vanadium High Speed Steel (HSSE) is made of high speed steel, carbon, vanadium carbide and other alloys to increase abrasive wear resistance and toughness. It is commonly used in general applications on stainless steels and high silicon aluminums.
Powdered Metal (PM) is tougher and more cost effective than solid carbide. It is commonly used on highly abrasive materials including high silicon aluminums.
Material Specific Color Band TapsSome manufacturers offer a color-coded identification system to help select high-performance taps. The color-coded band located on the shank indicates the type of material suitable for your application. The color bands are intended for increasing the life of the tap and for easy tool selection. For more information on color-band taps, contact MSC at (800) 645-7270 & ask for the Metalworking Tech Team. | |||||||
|---|---|---|---|---|---|---|---|
| Materials | Cutting Speed Ft./Min | TAPPING Hardness Brinell | Hardness Tons/ Sq. In | ||||
| BLUE BAND | |||||||
| Stainless Steels | |||||||
| Free Cutting | 12-35 | <250 | 56 | ||||
| Austenitic | 12-35 | <250 | 56 | ||||
| Martensitic, Ferritic | 12-15 | >300 | 63 | ||||
| Titanium | |||||||
| Pure Titanium, Unalloyed | 10-25 | <200 | 49 | ||||
| Titanium Alloys | 3-15 | >300 | 63 | ||||
| Nickel | |||||||
| Pure Nickel, Unalloyed | 10-15 | <300 | 63 | ||||
| GREEN BAND | |||||||
| Carbon Alloy Steels | |||||||
| Free Cutting Mild Steel | 25-50 | <120 | 27 | ||||
| Low Carbon Steel | 25-50 | <200 | 50 | ||||
| Medium Carbon Steel | 25-50 | <250 | 56 | ||||
| RED BAND | |||||||
| Carbon Alloy Steels | |||||||
| Low Alloy Steels | 6-30 | >250 | 56 | ||||
| Alloyed, Heat Treated | 6-30 | >300 | 63 | ||||
| Alloyed, Heat Treated | 6-30 | >350 | 74 | ||||
| Nickel | |||||||
| Nickel, Nimonic 75 | 10-12 | >300 | 63 | ||||
| Nickel, Inconel 718 Alloy | 10-15 | <350 | 74 | ||||
| Copper | |||||||
| High Tensile Bronze | 50-60 | <350 | 74 | ||||
| YELLOW BAND | |||||||
| Aluminum Alloys | |||||||
| Wrought & Extruded | 50-65 | <150 | 35 | ||||
| Wrought & Treated | 50-65 | >150 | 35 | ||||
| Cast, Low Silicon >5% | 50-65 | <150 | 35 | ||||
| Cast, High Silicon <10% | 50-65 | >150 | 35 | ||||
| Copper | |||||||
| Pure Copper | 50-60 | <100 | - | ||||
| Brass, Soft | 30-65 | <200 | 47 | ||||
| Brass, Bronze | 12-20 | >200 | 47 | ||||
| WHITE BAND | |||||||
| Cast Irons | |||||||
| Plain Grey Irons | 35-50 | <150 | 35 | ||||
| Plain “SG” Iron | 35-50 | <250 | 56 | ||||
| Alloy “SG” Iron Nickel Hard | 12-45 | >250 | 56 | ||||
| ORANGE BAND | |||||||
| Heat Resistant Alloys | |||||||
| Nickel-based Alloys | 10-20 | <350 | 75 | ||||
| Cobalt-based Alloys | 10-20 | <350 | 75 | ||||
| Super Alloys | 10-20 | <350 | 75 | ||||
| GREY BAND | |||||||
| Steels | |||||||
| Structural Steels | 35-60 | <450 | 75 | ||||
| Carbon Steels | 35-60 | <450 | 75 | ||||
| Alloy Steels | 35-60 | <450 | 75 | ||||
| Stainless Steels | |||||||
| Free Machining | 15-50 | <390 | 65 | ||||
| Austenitic | 15-50 | <390 | 65 | ||||
| Ferritic & Martensitic | 15-50 | <390 | 65 | ||||