Pull studs by taper
SK40 Pull Studs (Retention Knobs) – 15° Head, M16 and 5/8" Threads
SK40 pull studs (retention knobs) screw into the back of an SK40 tool holder (shank to DIN 69871, ISO 7388-1 form A) so the machine's drawbar can pull it into the spindle. PTP makes 7 SK40 pull studs: DIN 69872 with a 15° head, with M16 and 5/8" threads, solid or with a coolant hole. Every stud is CNC ground, MPT tested (Magnetic Particle Testing) and proof tested at 2.5× the clamping force.
All 7 SK40 pull studs
Grouped by standard, then by head angle. Each ordering code opens its own page with the drawing and every dimension (mm).
DIN 69872: 7 SK40 pull studs
| Ordering code | Head angle (θ) | Thread (TH) | Knob Ø (A) | Overall length (D) | Coolant hole Ø (J) | Seal |
|---|---|---|---|---|---|---|
| PSDA4003 | 15° | M16 | 17 mm | 54 mm | – | – |
| PSDA4003O | 15° | M16 | 17 mm | 54 mm | – | Seal ring |
| PSDA4003I | 15° | 5/8" | 16.28 mm | 54 mm | – | – |
| PSDAD4007 | 15° | M16 | 17 mm | 54 mm | 7 mm | – |
| PSDAD4007O | 15° | M16 | 17 mm | 54 mm | 7 mm | Seal ring |
| PSDAD4007OOT | 15° | M16 | 17 mm | 54 mm | 7 mm | Seal ring, O-ring |
| PSDAD4007I | 15° | 5/8" | 16.28 mm | 54 mm | 7 mm | – |
How do I choose an SK40 pull stud?
Taper. Check that the tool holder has an SK40 shank to DIN 69871, ISO 7388-1 form A. Its dimensions are on the SK (DIN 69871) shank page.
Standard. Pick the pull stud type your machine's drawbar is built for: DIN 69872.
Head angle. DIN 69872 15°. Check that your drawbar gripper takes the head angle you order.
Thread. The SK40 shank table gives M16 for the holder's pull-stud thread. The 5/8" version is for holders made with that thread.
Coolant. For through-spindle coolant, order a stud with a coolant hole (J, Ø7 mm); seal ring and O-ring versions seal it.
Questions about SK40 pull studs
What thread does an SK40 pull stud have?
SK40 pull studs from PTP come with M16 (5 codes) and 5/8" (PSDA4003I, PSDAD4007I) threads. The SK40 shank table gives M16 for the holder thread.
Which head angles are there for SK40 pull studs?
15° (DIN 69872). Order the head angle your drawbar gripper takes.
Are there coolant-through SK40 pull studs?
Yes: 4 of the 7 SK40 codes have a coolant hole, Ø7 mm (J); 3 have a seal ring and 1 has an O-ring. The table lists the coolant hole of every code.