Pagnoni SK Weldon End Mill Holders with Coolant Channels

Available Sizes and Part Numbers

Purpose and Application

Pagnoni WLK series Weldon holders with coolant channels are engineered by Italian manufacturer Pagnoni Tools SRL for CNC milling machines and machining centers with SK 40 and SK 50 spindles acc. to ISO 7388-1 (DIN 69871). Designed for heavy-duty and high-speed milling operations using DIN 1835 Form B Weldon shank cutting tools. The presence of longitudinal internal coolant channels supplies cutting fluid directly to the cutting edges, which is crucial when milling deep slots, cavities, and difficult-to-machine materials where external coolant flow is blocked by workpiece walls.

Design and Features

Tool locking is executed via a clamping screw bearing perpendicularly against the Weldon shank flat, entirely preventing tool rotation or slippage. For clamping diameters from 25 mm up (Ø 25, 32, 40 mm), holders feature two clamping screws. Internal coolant channels run along the bore length. Tooling is produced from case-hardened alloy steel heat-treated to HRC 58 ± 2 (case depth 0.4–0.5 mm). The body surface undergoes black oxide treatment (brunishing), while the taper is precision ground to quality < AT3 (DIN 7187 / DIN 2080). All chucks pass 100% final inspection and are dynamically balanced to G 6.3 at 12,000 rpm.

Compatibility

Tooling is designed for machine spindles with SK 40 and SK 50 tapers (ISO 7388-1 / DIN 69871). Compatible with solid carbide and indexable end mills, as well as drills featuring DIN 1835 Form B Weldon shanks. Holder mounting in the spindle is secured using pull studs conforming to DIN 69872 (e.g., Pagnoni 940TIR01, 950TIR01).

Selection Parameters

Selection is based on spindle taper (SK 40, SK 50) and clamping diameter d (6, 8, 10, 12, 14, 16, 18, 20, 25, 32, 40 mm). Gage lengths H (LPR) range from 50 mm to 120 mm. Coolant supply is implemented in Form AD/B (universal central or flange coolant supply).

Key Advantages:

• Direct Edge Coolant Supply: Built-in channels ensure forced cooling and efficient chip evacuation.
• Absolute Anti-Pullout Security: Clamping screw perpendicularly locks the Weldon shank by its side flat.
• Taper Accuracy < AT3: Precision-ground taper surface guarantees maximum contact with the spindle.
• 100% Quality Inspection: Complete verification of each product unit at the Pagnoni factory in Italy.
• Dual Clamping for Large Diameters: Executions from Ø 25 mm up feature two clamping screws for reliable torque transfer.