Precision CNC vices are used to hold workpieces with high accuracy on machining centres (CNC) and on vertical/horizontal and universal milling machines. Offering high repeatability (in the 0.003–0.005 mm range) and rigidity, these vices are essential for heavy cutting and tight-tolerance operations [00:21].

Watch Temak Teknik’s video below on the principles of using precision CNC vices, jaw design and the steps for correctly fixing the vice to the machine table:

Key Features and Design Details

1. Precision-Machined and Ground Surfaces: All surfaces, slideways and jaws of the vices are ground and precisely aligned with dowel pins [00:12].
2. Stepped/Pin-Type Quick Adjustment: Pin-type or stepped quick-positioning mechanisms are provided to shorten the long opening and closing times of the spindle screw [01:26].
3. Interchangeable Jaw Design: The jaws can be removed and reversed to obtain different height levels, or prismatic/V-groove replacement jaws can be fitted to hold cylindrical parts [01:34], [01:58].
4. Ground Tenons (T-Slot Compatible): Ground tenons on the underside of the base locate in the T-slots of the machine table, quickly aligning the vice with the axis in a vertical or horizontal position [03:47].

Correct Use and Workpiece Clamping Rules

• Clamp at the Centre: The workpiece should not be clamped at the very end of the jaws; clamping at the ends causes distortion and loss of concentricity. The part should be positioned at the centre of the jaws, or offset no more than ~10 mm from the centre, so that the clamping pressure is balanced [02:14], [02:29].
• Fixing to the Machine Table at 3 Points: When mounting the vice on the machine table, clamping with clamping claws at a minimum of 3 different points is essential for rigidity [03:15], [03:22].
• Alignment with a Dial Indicator: Even when the tenons are seated in the T-slot, a parallelism check should be carried out by placing a dial indicator against the vice jaw before heavy machining operations [04:13], [04:56].
• Workstop and Lock Nut: In series production, the workstop on the vice should be set so that parts are clamped in the same position, and its lock nut should be fully tightened to prevent loosening [07:36], [07:52].

Widely used in machining and assembly, countersinks are special cutting tools used to seat screw and bolt heads flush with the surface at hole entries, remove burrs and chamfer part edges.

Watch Temak Teknik’s information video on countersink types, angle options and application details below:

Main Functions of Countersinks

1. Preparing Screw Head Seats: Ensures countersunk-head bolts or screws sit fully flush without protruding from the part surface.
2. Deburring and Pre-Hole Enlargement: Removes burrs formed at the hole entry after drilling, producing a smooth surface.
3. Chamfering: Chamfers part corners and hole edges at specific angles to make assembly easier.

Countersink Types and Angle Selection

1. Countersinks by Cutting Angle

• 90° Countersinks: The most widely used standard type in the industry. Ideal for countersunk bolt seats to DIN 7991 and ISO 10642 and for deburring.
• 60° Countersinks: Preferred for opening centre hole entries and special chamfering operations.
• 82° and 100° / 120° Countersinks: Generally used in aerospace, medical and special machine building to create seats for different screw standards.

2. By Design Type

• 3-Flute (Multi-Flute) Countersinks with Cylindrical Shank: This widely used design distributes the cutting force evenly across three flutes, delivering a vibration-free, smooth surface finish.
• Cross-Hole Countersinks (Deburring Countersinks): The transverse hole in the conical body draws the chips inwards and evacuates them. They cut cleanly without leaving burrs, especially in soft metals (aluminium, brass) and plastics.
• Fixed-Pilot Counterbores/Countersinks: The cylindrical pilot at the front keeps the tool exactly on the hole axis, so that cylindrical or conical head seats (e.g. socket head cap screw counterbores) are produced without misalignment.

Material and Coating Options

• HSS and HSS-Co (5% Cobalt): The common standard solution for general engineering steels, castings and cast iron. Cobalt-alloyed versions offer greater resistance to heat and wear.
• Carbide Countersinks: Deliver long tool life at high speeds in high-hardness materials (hardened steels, stainless steel etc.) and on CNC machines in series production.
• TiN (Titanium Nitride) Coating: Reduces friction, improves lubricity and significantly increases tool life.

Usage and Application Recommendations

• Speed and Feed: In countersinking operations, high spindle speeds and fast feeds can cause vibration (chatter marks). It is therefore recommended to work at low speed with steady, controlled pressure.
• Axial Centring: Exact alignment of the countersink with the hole axis is critical for balanced load distribution and a smooth surface finish.

Used in workshops for fast, practical and precise threading of large and small workpieces, the Krasnic Electric Tapping Machine makes the operator’s job considerably easier thanks to its high torque and articulated arm mechanism.

Watch Temak Teknik’s video below explaining the machine’s technical specifications and operating modes:

Key Technical Specifications

• Tapping Capacity: Taps threads over a wide range from Metric 6 to Metric 30 (M6 – M30) [00:00].
• Power Requirement: Runs on a standard 220 V mains supply [00:09].
• Spindle Speed: Reaches a maximum speed of 200 revolutions per minute (RPM) [00:09]. Forward and reverse speeds can be set independently (e.g. 150 RPM in, 200 RPM out) [01:08].
• Holding System: Uses torque-limiting adaptors with a 31 mm shank diameter [01:30].
• Display & Interface: Features an easy-to-use digital touchscreen control panel with a Turkish-language interface [00:24].

Operating Modes of the Machine

1. Manual Mode

   • After locating the tap in the hole, the operator taps the thread by holding down the button on the arm [02:05].
   • Once tapping is complete, the operator presses the reverse button to withdraw the tap from the hole [02:21].

2. Automatic Mode

   • The target hole depth (e.g. 15 mm) is set on the display [00:59].
   • With a single press of the Start button, the machine taps to the preset depth and, on reaching it, automatically reverses and withdraws from the hole [02:46].

3. Peck Tapping Mode

   • Used especially for deep holes or materials with a high risk of chip packing [00:30].
   • The peck depth and retract distance are set on the display (e.g. advance 5 mm, retract 2 mm) [03:23].
   • The machine advances step by step, breaking the chips, and withdraws automatically once the operation is complete [04:20].

The Krasnic Drill Bit Grinder is used in machining and workshop environments to resharpen dull drill bits quickly, conveniently and precisely.

Watch Temak Teknik’s video below explaining the box contents of the Krasnic drill sharpening machine, the drill bit zeroing steps and the 2-stage grinding process:

Capacity and Box Contents

• Grinding Diameter Capacity: Capable of grinding drill bits from 2 mm to 13 mm [00:00].
• Standard Equipment: Supplied with 11 ER collets, 1 collet adaptor/chuck, a power cable and a Carbide (Diamond) Grinding Wheel fitted to the machine [00:13]. (An HSS Grinding Wheel should be obtained as an option for sharpening HSS drills [00:24]).
• Adjustable Point Angles: The point angle on the machine is set to the standard 118° but can easily be adjusted to 90°, 118°, 130°, 135° and 140° point angles as required [03:15], [03:27].

Step-by-Step Drill Grinding Process

1. Collet and Diameter Setting: A collet suited to the diameter of the drill to be sharpened (e.g. 8 mm) is selected and seated in the adaptor [00:36].
2. Zeroing the Point Length and Angle: The adaptor is fitted to the zeroing station on the machine. The diameter dial is set to the diameter of the drill to be sharpened (8 mm), the drill bit is pushed in up to the stop, the cutting edges are aligned parallel to the shoulder and the adaptor is tightened [01:05], [01:57].
3. Stage 1 – Grinding the Main Point Angle: With the machine running, the adaptor is inserted into the main grinding station. It is ground with gentle left-right movements until the grinding sound stops [02:10], [02:27]. The adaptor is then rotated 180° and the other cutting edge is ground in the same way [02:40].
4. Stage 2 – Grinding the Relief/Clearance Angle: Move to the second grinding station. The lugs on the adaptor are aligned with the slot and the relief angle is applied with left-right movements [03:27], [03:55]. Rotating it 180° completes the other side, and the drill bit is ready for use [04:02].

Producing accurate threads in machining and workshop practice is critical both for workpiece quality and for the life of the tap. Choosing the wrong tap or drilling an incorrect hole diameter can lead to tap breakage, loose threads and significant loss of time.

In this article, guided by Temak Teknik, we cover in detail the parameters for correct tap selection, tap types, tap drill size calculation and the steps for hand tapping.

1. Key Parameters to Consider When Selecting a Tap

When selecting a tap, you should first consider your production conditions and the structure of the material to be machined:

• Production Quantity and Method: For small batches, hand taps or simple machine taps can be used. In series production, CNC or automatic tapping machines should be preferred.
• Cutting Direction: Depending on the application requirements, determine whether a right-hand or left-hand thread is to be cut.
• Material Structure: The hardness, toughness and softness of the material, and the type of chip it produces, directly affect tap selection.
• Tolerance Classes: The tolerance class marked on the tap (e.g. 6H, 6g) must match the technical drawing, and the threads produced must always be checked with a thread gauge.

2. Tap Types and Applications

Taps are divided into different categories according to their helix angles and chamfer forms:

• Form A Taps: Have a 6–8 pitch chamfer length and a 5° chamfer angle. Preferred for through holes in short-chipping materials.
• Form B Taps: Among the most common types in the field. Have a 3.5–5.5 pitch chamfer length and an 8° chamfer angle.
• Form C Taps: Have a 2–3 pitch chamfer length and a 15° chamfer angle. Used especially as spiral flute taps for short-chipping materials and in blind holes.
• Form E Taps: Preferred for narrow blind holes where the thread must be cut right to the bottom of the hole (1.5–2 pitch, 23° chamfer angle). Note: The shorter the chamfer, the shorter the tap life will be.

3. Tap Drill Size Calculation and Preparation

There are two vital steps to observe before tapping:

Drill Diameter Calculation

Before tapping, the diameter of the hole to be drilled is calculated with the following practical formula:

Hole Diameter = Nominal Diameter − Pitch

• Example: For a metric 10 (M10) tap, the pitch is 1.5 mm.

Hole Diameter = 10 − 1.5 = 8.5 mm

If an arbitrary drill bit is used instead of 8.5 mm, the threads may not engage or the screw will fit loosely (with play).

Countersinking and Lubrication

• Countersinking: The hole must always be countersunk after drilling. This allows the tap to start easily and prevents material bulging and tap breakage.
• Use of Cutting Oil: Cutting oil must always be used during the operation. Lubrication facilitates chip evacuation, reduces friction and ensures a smooth thread surface.

4. How to Hand Tap, Step by Step

Hand tapping generally uses sets of 3 hand taps:

1. No. 1 Tap (One Ring): The taper (starting) tap.
2. No. 2 Tap (Two Rings): The intermediate tap.
3. No. 3 Tap (No Ring): The bottoming (finishing) tap that completes the thread.

Application Steps

1. Starting and Squaring: After countersinking the hole, the No. 1 tap is positioned. To ensure the tap enters the part at exactly 90°, it is checked from two different angles (with a square or by eye) as it is started.
2. Lubrication: A few drops of cutting oil are applied to the tap flutes.
3. Advancing While Breaking the Chip: The tap wrench is turned evenly. When the tap begins to bind, it is turned back slightly every half/full turn to break the chip.
4. Using the Remaining Taps in Sequence: After removing the No. 1 tap, the operation is completed by running the No. 2 and then the No. 3 tap, taking care to follow the same thread path.

Important Tip: Make sure the force you apply to the tap wrench is equal and balanced on both handles. Axial misalignment easily causes small-diameter taps to break.

In machining operations such as tapping, threading with dies, drilling and milling, Tapping Oil (cutting and threading oil) is a vital auxiliary fluid that reduces friction and heat, extending tool life.

Watch Temak Teknik’s video explaining the use of tapping oil, its benefits and application methods below:

Key Benefits of Tapping Oil

1. Prevents Friction and Overheating: Tapping is a high-friction cutting operation. The high heat generated by dry cutting, especially in synthetic materials such as plastics, cast nylon, Delrin and polyamide, damages the material structure and causes smoke [00:18], [00:28].
2. Increases Tool Life: Compared with dry tapping, using tapping oil increases the life of the tap and drill by 2 to 3 times, delivering significant cost savings [01:45], [01:52].
3. Improves Surface Quality: By minimising heat and friction, it prevents burrs on the thread profiles, producing smooth and accurate threads [01:21].
4. Chip Evacuation: Thanks to its synthetic and mineral-based composition and high viscosity, it helps chips slide out of the flutes easily [01:11].
5. Corrosion and Rust Protection: It leaves a protective oil film on the part after cutting, preventing the threads from rusting and oxidising over time [00:53], [01:01].

Correct Application Method

• Economical Application: Tapping oil should not be applied excessively. A few pea-sized drops on the tap flutes or drill tip are entirely sufficient for the operation [01:45], [02:55].
• Applications: Widely used in manual tapping and in operations on pillar drills, tapping machines, lathes and milling machines [02:19].
• Note for CNC Machines: For safety reasons, applying oil by hand inside enclosed CNC machines is not recommended; on CNC machines, coolants (soluble oil emulsion) delivered through the tool or via external nozzles should be used instead [02:31].

In machining operations (on CNC machining centres, lathes and pillar drills), tapping heads (tap holders) are used to prevent breakage of the taps used for cutting screw threads and to achieve an accurate thread pitch.

Watch Temak Teknik’s informative video below showing the types of tapping heads, their float mechanism and quick tap changing:

Working Principle and Advantages of Tapping Heads

1. Spring Compensation and Synchronisation (Float Mechanism): When tapping ends, or at the moment the spindle reverses from clockwise to anticlockwise rotation, momentary synchronisation differences can occur between the machine’s Z-axis feed and its rotation. The axial spring mechanism inside the head compensates for this difference and play, absorbing the excess load on the tap [00:18].
2. Preventing Tap Breakage and Extending Tool Life: The float springs cushion sudden loads caused by chip packing during cutting or at the moment of reversal. This prevents the tap from chipping or breaking, avoiding scrapped workpieces and damage to the machine [01:24].
3. Fast and Easy Tap Change: Thanks to the secure ball/latch mechanism on the head, the tap can be changed easily within seconds, with or without an adaptor, without removing the holder from the spindle or turret [00:59].

Connection and Shank Types

• Machine Connection Types: For machining centres and lathes, BT30, BT40, BT50 and HSK-63 taper types are available, as well as straight (cylindrical) shank models and special taper types for drilling machines [01:53].
• Size and Metric Adaptor Selection: For each thread size (e.g. M6, M8, M10, etc.), a tap adaptor of the appropriate size is inserted into the holder. For taps of different diameters, a head or tap adaptor of the matching size should be selected [02:23].

Fitting and Changing Steps

1. Fitting the Mechanism: The tap adaptor is seated in its socket and locked by pulling back the collar on the main body [02:42].
2. Securing the Tap: The tap of the corresponding metric size is inserted into the socket by pressing the locking mechanism at the front of the adaptor [03:00].
3. Movement Check: Once fitted, the system has no radial (side-to-side) play; it provides axial float only along the Z axis (up and down) [03:13].

In machining, taps are used for internal threading of detachable and re-fittable fastening elements. Choosing the right tap type for the material and manufacturing method extends tool life and improves thread quality.

In this article, guided by Temak Teknik, we examine the types of taps, their applications, tap substrate materials and coating properties.

1. Types of Taps by Working Principle

Hand Taps (Set of 3)

Tools made from HSS, generally used in manual applications:

• No. 1 Tap (Single Ring) – Taper: Has a long chamfer and taper and is used to start the thread.
• No. 2 Tap (Double Ring) – Intermediate: The intermediate tap that deepens the thread profile.
• No. 3 Tap (No Ring) – Bottoming: The finishing tap that sizes the thread and completes the tapping operation.

Machine Taps

• Straight Flute Taps: Preferred for through holes (open-ended holes).
  • Straight Flute Type: Collects the chips in the centre of the flutes.
  • Spiral Point (Gun Nose) Type: Pushes the chips straight ahead and down.
• Spiral Flute Taps: Because they evacuate chips upwards instead of pushing them down, they can be used reliably in blind holes (closed holes) as well as through holes.
• Forming (Roll) Taps: Produce the thread form by displacing the material without removing chips. Preferred in the series production of soft materials such as copper, aluminium and brass.
• Interrupted Thread Taps: Feature alternate teeth removed from the thread. Used in soft materials such as polyamide or aluminium and for fine threads to increase strength.

2. Tap Substrate Materials

Taps have different substrate compositions depending on the hardness of the workpiece and the operating conditions:

• HSS (High-Speed Steel): Commonly preferred, generally for hand taps.
• HSS-E (5% Cobalt): The most common type for machine taps. Its cobalt content provides wear resistance and high heat resistance.
• HSS-M (PM / Powder Metallurgy): Provides long tool life in difficult materials such as nickel alloys, stainless steel and titanium.
• HSS-E V3: Delivers outstanding performance when tapping high-hardness materials.

3. Coatings and Colour Codes

• Coated Taps: Although the initial purchase cost may seem high, the lubricity, high wear resistance and long tool life they provide significantly reduce the total manufacturing cost.
• Colour Codes: Manufacturers add colour codes such as blue, red, black or yellow to tap shanks to indicate the material group the tap is suited to, its coating type and its application.

In machining and workshop applications, drill chucks are basic holding devices used to clamp tools such as drill bits, centre drills or reamers quickly, conveniently and economically.

Watch Temak Teknik’s video below detailing the use of drill chucks on CNC and drilling machines and the selection criteria:

Key Features and Types

1. Fast, Keyless Changeover: Drill chucks allow drill bits within certain diameter ranges (e.g. 1–13 mm or 1–16 mm) to be clamped and released conveniently, without the need for additional collets or reduction sleeves [00:37].

2. Types of Drill Chucks

   • Keyed / Geared Drill Chucks: Models tightened using a chuck key on the side. Commonly used on pillar drills and hand drills [00:19].
   • Precision / CNC-Type Drill Chucks: Versions with a wrench slot or tightened directly by hand, used on CNC machining centres to increase torque and achieve higher runout accuracy [00:11].

Correct Use and Limitations

• Three-Point Clamping Principle: Drill chucks hold the tool with three internal jaws [01:00].
• No Side Cutting (Not Suitable for Milling Cutters): Lateral cutting operations must never be performed with an end mill or reamer fitted in a drill chuck [00:49]. Radial (lateral) forces damage the jaws and cause the tool to run out or be ejected [01:12]. Drill chucks are designed only for axial (drilling) forces.

In machining, cutting a thread on the external surface of shafts or cylindrical parts is known as threading with a die. To obtain high-quality threads with the correct tolerance that tighten easily, it is extremely important to turn the blank to the correct diameter and use the right techniques before threading.

In this article, with guidance from Temak Teknik, we cover the principles of die threading, clearance calculation, mounting the die in the die stock and a step-by-step threading procedure.

1. Blank Diameter and Clearance Calculation Before Threading

The diameter of the shaft to be threaded is not machined exactly to the target nominal metric diameter. For example, if an M10 thread is to be cut and the shaft diameter is made exactly 10.00 mm, the threads will bind or fail to engage with the nut.

For the nut and bolt to run freely, the shaft diameter should be reduced by 10% to 20% (approx. 0.15 mm) (running clearance).

Running Clearance Formula

Blank Diameter = Nominal Diameter − (0.1×Pitch)

• Example (for M10)

  • Nominal Diameter: 10 mm
  • Pitch: 1.5 mm
  • Blank Diameter = 10 − (0.1×1.5) = 9.85 mm
  • Therefore, a shaft to be threaded M10 with a die should be turned to a diameter of approximately 9.80 – 9.85 mm.

Warning: If the shaft diameter is reduced more than necessary, threading becomes easier, but the strength of the resulting threads decreases and the joint will have play.

2. The Importance of Chamfering and Thread Relief

• Chamfering: To allow the die to start easily on the shaft, an approximately 45° chamfer should be filed or turned on the end of the shaft.
• Thread Relief: If the thread must run right up to the end of the shaft (flush with the shoulder), a relief groove should be turned at the base of the shaft during turning.

3. Mounting the Die in the Die Stock

• The notch/recess on the die is positioned to line up with the locking screw in the die stock.
• The side screws are tightened to centre and secure the die in the stock.
• Because the die has a lead chamfer on both faces, either side can be used.

4. Step-by-Step Die Threading Procedure

1. Clamping and Squaring the Part: The workpiece is clamped in a vice. The die stock is positioned exactly square and parallel to the shaft. If the die is started at an angle, the threads will drift axially, shallow threads will form or the die may break.
2. Lubrication: Always apply cutting oil to the shaft and die to make cutting easier and improve thread quality.
3. Advancing While Breaking Chips: The die is turned with even pressure. After advancing a few turns, the die is turned back following the one turn forward, half a turn back principle to break the chips.
4. Cleaning and Checking: Once the required length is reached, the die is backed off, the chips are cleaned from the threads and a suitable nut is used to check that the thread runs freely.