Pull studs by taper
SK50 Pull Studs (Retention Knobs) – 15° Head, M24 and 1" Threads
SK50 pull studs (retention knobs) screw into the back of an SK50 tool holder (shank to DIN 69871, ISO 7388-1 form A) so the machine's drawbar can pull it into the spindle. PTP makes 6 SK50 pull studs: DIN 69872 with a 15° head, with M24 and 1" 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 6 SK50 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: 6 SK50 pull studs
| Ordering code | Head angle (θ) | Thread (TH) | Knob Ø (A) | Overall length (D) | Coolant hole Ø (J) | Seal |
|---|---|---|---|---|---|---|
| PSDA5032 | 15° | M24 | 25 mm | 74 mm | – | – |
| PSDA5032O | 15° | M24 | 25 mm | 74 mm | – | Seal ring |
| PSDA5032I | 15° | 1" | 26.17 mm | 74 mm | – | – |
| PSDAD5004 | 15° | M24 | 25 mm | 74 mm | 11.5 mm | – |
| PSDAD5004O | 15° | M24 | 25 mm | 74 mm | 11.5 mm | Seal ring |
| PSDAD5004I | 15° | 1" | 26.17 mm | 74 mm | 11.5 mm | – |
How do I choose an SK50 pull stud?
Taper. Check that the tool holder has an SK50 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 SK50 shank table gives M24 for the holder's pull-stud thread. The 1" version is for holders made with that thread.
Coolant. For through-spindle coolant, order a stud with a coolant hole (J, Ø11.5 mm); seal ring versions seal it.
Questions about SK50 pull studs
What thread does an SK50 pull stud have?
SK50 pull studs from PTP come with M24 (4 codes) and 1" (PSDAD5004I, PSDA5032I) threads. The SK50 shank table gives M24 for the holder thread.
Which head angles are there for SK50 pull studs?
15° (DIN 69872). Order the head angle your drawbar gripper takes.
Are there coolant-through SK50 pull studs?
Yes: 3 of the 6 SK50 codes have a coolant hole, Ø11.5 mm (J); 2 have a seal ring. The table lists the coolant hole of every code.