What are the different grades of pdc cutter

Introduction

A PDC drill bit is only as good as the cutters mounted on its face, and those cutters come in a range of grades that many buyers find confusing. Codes like 1308, 1313, and 1613 appear in every catalog, but they are not random numbers. They describe the size, the diamond layer, and the performance level of each cutter. Understanding these grades is the first step to picking a bit that drills fast, lasts long, and does not waste your budget.

What a PDC Cutter Is Made Of

A PDC cutter (polycrystalline diamond compact) is a small disc built from two layers. The top layer is polycrystalline diamond, a synthetic material almost as hard as natural diamond, and it does the actual cutting. Underneath sits a tungsten carbide substrate that supports the diamond and locks the cutter into the bit body. The two layers are fused under extreme heat and pressure, and the quality of that bond decides how long the cutter survives downhole. In practice, the grade of a cutter is a short way of describing its diamond quality, its dimensions, and how it was made.

Size Grades: Reading the Four-Digit Code

The most common way to grade a PDC cutter is by size. The code is read in two parts: the first two digits are the diameter in millimetres, and the last two are the total height. A 1308 cutter is 13 mm across and 8 mm tall; a 1613 cutter is 16 mm across and 13 mm tall. The grades you will meet most often are 1308, 1313, 1613, 1913, and 1916, along with smaller sizes such as 0804 and 0808 for lighter tools. Larger cutters expose more diamond and remove rock faster, but they need more weight on the bit and chip more easily in hard ground. Smaller cutters are tougher for their size but cut more slowly, so the right choice always depends on the formation.

Quality Grades: Standard, Premium, and Thermally Stable

Size is only half the story. PDC cutters are also graded by quality and performance. Standard grades handle soft to medium formations and moderate temperatures without trouble. Premium grades use a thicker or more carefully sorted diamond layer and wear more slowly in abrasive rock. Thermally stable, or leached, grades have the metal catalyst removed from the diamond layer, which lets them run hotter without the diamond turning back into graphite. These are the grades to specify for deep wells and hard, silica-rich formations where heat builds up fast.

Diamond Table and Chamfer Grades

Two more details separate one grade from another. The diamond table thickness, usually between 2.0 mm and 3.0 mm, controls how much abrasive wear the cutter can absorb before the carbide underneath is exposed. The chamfer, a small bevel ground onto the cutting edge, controls the balance between sharpness and strength. A larger chamfer makes the edge tougher and more impact resistant, while a smaller one keeps the cutter aggressive. Getting these two parameters right for the rock is where experienced bit makers add the most value.

How to Choose the Right Grade

Start with the formation report. In soft shale, mudstone, and sandstone, a standard 1308 cutter with a small chamfer gives the fastest penetration. In medium-hard limestone and interbedded rock, a 1313 or 1613 grade with a slightly larger chamfer balances speed against durability. In hard, abrasive, or high-impact ground, move to a thicker diamond table, a bigger chamfer, or a thermally stable grade. If you cannot predict the ground, the 1308 grade is the sensible default because it covers the widest range of conditions.

Where to Source PDC Cutters

TY Drill Bits (Xi'an Heaven Abundant Mining Equipment Co., Ltd) has been making drilling tools since 2010 and supplies PDC cutters in the common grades, including 1308, 1313, 1613, and 0804, for PDC drill bits and stone cutting. The factory is ISO9001 certified, offers OEM service, and exports worldwide, with most orders delivered within fifteen working days. Their team can match a cutter grade to your formation and your budget, whether you need a few spares or a full container.

Frequently Asked Questions

Q: What does 1308 mean on a PDC cutter?
A: It means a 13 mm diameter and an 8 mm height. The four-digit code always lists diameter first and height second.

Q: Is a bigger cutter always better?
A: No. Bigger cutters drill faster in soft rock but chip more easily in hard or abrasive formations. The best grade depends on the rock you are drilling.

Q: What is a thermally stable PDC cutter?
A: It is a cutter with the metal catalyst leached out of the diamond layer, so it keeps cutting at higher temperatures without degrading.

Q: Can I buy PDC cutters in small quantities?
A: Yes. Many suppliers, including TY Drill Bits, sell cutters in bulk and in smaller lots, and can recommend the right grade for your application.

Conclusion

The grade of a PDC cutter is not just a number on a spec sheet. It is the combination of size, diamond quality, thermal stability, and edge geometry that decides how fast and how long your bit will drill. Match the grade to the formation and you save money on every metre. If you are planning a drilling program or sourcing cutters in volume, talk to TY Drill Bits about the right grade for your rock.