B2B one-stop procurement, global machine tool accessories supplier

One-stop shopping for machine tool accessories

WC vs. SP Indexable U-Drills: The Ultimate Selection Guide for Distributors

Created on 11.29

As a distributor of CNC cutting tools, one of the most common questions you likely receive from your end-users is: "Should I choose the WC type or the SP type U-Drill?"

At OLI CNC Tools, we understand that carrying the right inventory is crucial for your business. While both drills look similar and serve the general purpose of high-speed drilling, they are designed for different applications.

Based on our sales data and technical specifications, this guide breaks down the differences between WC and SP blade U-Drills to help you recommend the right product to your customers and optimize your stock.

Comparison of WC and SP drill inserts for machining efficiency and hole suitability.

1. The WC Series U-Drill (The Market Leader)

Insert Type: WCMX / WCMT (Trigon Shape)Market Share: Approx. 70% of Customers

The WC series is the "workhorse" of the indexable drilling world. It is the most popular choice for general machining shops.

Key Selling Points for Your Customers:

High Efficiency:

 The design allows for excellent chip evacuation and slightly higher drilling speeds compared to the SP series.

Cost-Effective:

 WC inserts are generally more affordable, making them ideal for high-volume production.

3 Usable Edges:

 The trigon insert offers three cutting edges.

Best Application:

 Through-Hole Machining. If your customer is drilling holes that go all the way through the workpiece, the WC drill is the most efficient choice.

Distributor Tip: Since 70% of customers prefer this type, the WC series should make up the bulk of your U-Drill inventory.

2. The SP Series U-Drill (The Precision Specialist)

Insert Type: SPMG / SPMT (Square Shape)Market Share: Approx. 30% of Customers

The SP series is designed for stability and surface quality. While it holds a smaller market share, it is indispensable for specific mold and die applications.

Key Selling Points for Your Customers:

Superior Finish:

 The SP drill provides a better surface finish on the hole walls compared to the WC type.

Flat Bottom Geometry:

 This is the critical difference. The SP drill creates a much flatter bottom than the WC type.

4 Usable Edges:

 The square insert shape allows for 4 cutting edges, offering extended tool life per insert.

Best Application:

 Blind-Hole Machining. If your customer needs a flat-bottom hole or requires a high-quality finish without a secondary boring operation, the SP is the superior choice.

Distributor Tip: Stock the SP series for your customers in the mold making industry or those requiring high-precision blind holes.

Side-by-Side Comparison

Feature	WC Series U-Drill	SP Series U-Drill
Matching Insert	WCMX / WCMT	SPMG / SPMT
Insert Shape	Trigon (Triangle-like)	Square
Usable Edges	3 Edges	4 Edges
Hole Bottom	Irregular / Wavy	Relatively Flat
Primary Application	Through-Holes	Blind-Holes
Drilling Efficiency	High	Medium-High
Market Popularity	★★★★★ (70%)	★★★ (30%)

Available Depth Ratios:

2D / 3D: For standard short-hole drilling.

4D / 5D: For deep-hole drilling applications.

Diameter Coverage:

WC Series: From 14mm up to 60mm.

SP Series: From 13mm up to 52mm.

Conclusion: Which Should You Order?

To maximize your sales revenue:

Focus on WC Drills

 for general engineering workshops and high-volume production lines where cost per part and speed are priorities.

Upsell SP Drills

 to mold shops and precision manufacturers who value hole finish and flat bottoms over raw speed.

Ready to restock your warehouse?Contact OLI CNC Tools today for our latest wholesale price list and catalog. We provide consistent quality and competitive pricing to help you grow your business.

Company News

ALL

Company News

Exhibition Information

Product Showcase

Industry Trends