When browsing through catalogs of High-Speed Steel (HSS) drill bits, you will frequently encounter two main descriptions regarding their manufacturing process: "Roll Forged(RF)" and "Full Ground (FG)".
At Jiacheng Tools, we believe an informed customer is our best customer. While both types of drills look similar at a glance, the way they are made significantly impacts their performance, price, and ideal application. Understanding this difference is important for purchase managers and end-users to ensure cost-efficiency and operational precision.
In this week's update, we break down the manufacturing processes to help you choose the right tool for the job.
The Basics: It’s All About How the Flutes Are Formed
The fundamental difference lies in how the spiral flutes (the grooves that remove chips) and the outer diameter are created from the raw steel rod.
1. What is a Roll Forged Drill Bit? (The Economical Warrior)
The Process: Roll forging is essentially a high-heat molding process. A steel blank is heated until it is malleable and then passed through specially designed rollers that "forge" or press the flutes into shape. It’s similar to how dough is rolled into pasta shapes.
Characteristics:
● Appearance: Often has a black oxide finish. The edges might feel slightly smoother or rounder compared to ground bits.
● Precision: Because the metal is pressed rather than cut, the tolerances are generally looser. The concentricity (how truly centered the bit spins) is acceptable for general tasks but less precise than ground options.
● Cost: This is a high-speed, mass-production method, making roll forged drills significantly cheaper to produce.
Best For: DIY projects, wood, soft metals, and general construction work where extreme precision is not critical, and budget is a primary concern.
2. What is a Full Ground Drill Bit? (The Precision Expert)
The Process: As the name implies, a full ground drill starts as a hardened solid steel blank. The flutes, the outer diameter, and the point are all precision-ground using abrasive grinding wheels. No heat deformation is involved in shaping the flutes.
Characteristics:
● Appearance: Usually bright, shiny bare metal (or coated with TiN/cobalt), with very sharp, defined edges on the flutes.
● Precision: The grinding process allows for extremely tight tolerances. The drill is highly concentric, ensuring accurate hole sizes and straighter drilling.
● Performance: The grinding process does not disrupt the steel's grain structure as much as heating does, often resulting in a tougher bit. The sharper cutting edges evacuate chips faster and generate less heat.
Best For: Professional industrial use, CNC machining, drilling harder metals (like stainless steel or alloy steel), and applications requiring high accuracy and long tool life.
Why Does This Matter to Your Business?
Choosing the wrong type of drill bit can lead to two types of waste:
1. Overpaying: Using a premium Full Ground bit for drilling simple holes in lumber is unnecessary cost.
2. Underperforming: Using a Roll Forged bit on tough stainless steel will lead to rapid dulling, broken bits, poor hole quality, and expensive machine downtime.
The Jiacheng Tools Promise
At Jiacheng Tools, we offer both varieties because we know the market needs both.
However, we emphasize quality consistency regardless of the process.
● For our Roll Forged lines, we ensure high-quality HSS material is used to maximize durability within that category.
See product details:
● For our Full Ground series, we utilize state-of-the-art CNC grinding machinery to guarantee the precision required by modern industry standards (such as DIN 338/DIN 1897).
See product details:
https://www.jiachengtoolsco.com/high-performance-fully-ground-hss-twist-drill-bits-product/
Need help selecting the right drill bit series for your inventory or application? Contact Jiacheng Tools today. Our engineers are ready to assist you in balancing performance and cost.
Post time: Jan-22-2026