SP is a 55° positive trigon insert family with positive rake, sharp cutting edges, and low cutting force — preferred for stainless steel, aluminum, low-carbon steel, and thin plate work where reduced cutting pressure and good chip flow matter. WC is an 80° trigon (negative rake) insert family with strong cutting edges for steel, alloy steel, and cast iron at high material removal rate. Both are indexable U-drill standards. For 5D very-deep drilling on stainless / aluminum, SP is the better choice. For very-deep drilling on steel at high MRR, WC is typically preferred for rigidity.

5D depth ratio is the deepest practical ratio for standard SP/WC indexable U-drill bodies. It covers aerospace structural work, long-reach mold base, and other very-deep drilling where 4D can't reach. Beyond 5D, use the 12D Saber Tooth Drill with sword-tooth insert geometry designed for extra-deep rigidity. 5D requires the highest coolant pressure (20-40 bar) and mandatory peck-cycle. For most production drilling, 3D or 4D is sufficient — 5D is reserved for cases where the deeper reach is essential.

Yes. All BEYOND SP 5D indexable U-drill bodies in this collection (C20 / C25 / C32 / C40 shanks) have through-body internal coolant channels. At 5D depth, internal coolant is mandatory and very-high-pressure for stable chip evacuation. Coolant pressure requirements: 20-25 bar for small shanks, 25-30 bar for medium, 30-40 bar for heavy. Additionally, peck-cycle is mandatory (retract every 0.3-0.5× the drill diameter) to break chips before they pack in the deep flutes.

Yes. All BEYOND SP 5D drill bodies follow ISO 1832 standard for SPGT (positive trigon ground) and SPMT (positive trigon molded) inserts. Cross-brand equivalents from Korloy, Mitsubishi, Sumitomo, and Sandvik will fit the same pocket. The only check needed is IC size (5.0 / 6.0 / 7.0 / 9.0 / 11.0 / 14.0 mm) and matching insert thickness. For grade selection, see the 8-brand grade cross-reference.

General rule: shank diameter should be at least 70-80% of the cutting diameter for rigidity without over-stressing the spindle. For 13-22mm drill, use C20 shank (9 SKUs). For 18-30mm drill, use C25 shank (25 SKUs). For 26-37mm drill, use C32 shank (27 SKUs). For 38-50mm drill, use C40 shank (13 SKUs). Bigger shank = more rigid setup but heavier spindle load. The full shank × insert cross-reference is in the table above.

Peck-cycle (retract drill periodically to break chips) is mandatory for all materials at 5D — without it, chips pack in the deep flutes and cause drill breakage. Standard peck-cycle interval is 0.3-0.5× the drill diameter — for a 25mm drill, retract every 8-12mm. For stainless steel and other stringy-chip materials, use the shorter interval (0.3×). For steel / cast iron with shorter chip, the longer interval (0.5×) works. The Speeds & Feeds hub has detailed peck-cycle guidance.