Rock River Tool, Inc.Precision Cutting Tools
Technical Support(800) 345-8924
Talk to an Engineer Engineered for high accuracy, extreme straightness, and exceptional surface finish in metalworking shops across Istanbul and the Marmara region.
Deep hole drilling—defined as producing holes with a length-to-diameter ratio ($L/D$) exceeding $10:1$ up to $100:1$ or higher—represents one of the most demanding metal-cutting operations in modern manufacturing. As Turkey's industrial heartland, Istanbul and surrounding zones such as Kocaeli (Gebze), Tuzla, and İkitelli OSB have evolved into major centers for automotive components, aerospace structures, defense equipment, and plastic injection mold making. To maintain global competitiveness, regional precision machining facilities require tooling suppliers capable of delivering absolute hole straightness, minimal centerline drift, and surface finishes surpassing $Ra\ 0.4\ \mu\text{m}$.
The primary challenge in deep hole drilling is continuous chip evacuation and heat dissipation from an enclosed cutting zone. A high-performance gundrilling system relies on high-pressure coolant delivered internally through the tool's coolant hole. The fluid cools the cutting edge, lubricates the tungsten carbide wear pads, and flushes chips out along the V-shaped external flute channel.
For Istanbul machine shops operating both specialized deep hole drilling machines (such as Eldorado, Botek, or Mollart systems) and standard multi-axis CNC machining centers equipped with high-pressure coolant pumps ($70–140\text{ bar}$), selecting the right carbide grade and edge geometry is vital. Our tools incorporate specially designed kidney-shaped or dual-round coolant passages to maximize volumetric flow rate, eliminating chip packing and catastrophic tool breakage.
| Workpiece Material | Hardness Range | Carbide Grade (ISO) | Cutting Speed ($V_c$, m/min) | Coolant Pressure (Bar, $\varnothing 3-10\text{mm}$) |
|---|---|---|---|---|
| Unalloyed Steels (C45, St52) | 160–220 HB | C5 / C6 (P20–P30) | 70 – 110 | 60 – 90 Bar |
| Alloy / Mold Steels (P20, 42CrMo4, H13) | 28–44 HRC | C6 / TiAlN Coated | 45 – 75 | 70 – 110 Bar |
| Austenitic Stainless (304, 316L) | 180–240 HB | Micrograin C2 (M20) | 35 – 55 | 80 – 120 Bar |
| Cast Iron (GG25, GGG40) | 180–250 HB | C2 (K10–K20 / 883) | 80 – 130 | 50 – 80 Bar |
| Aluminum & Non-Ferrous Alloys | 60–120 HB | Uncoated C2 Polished | 120 – 220 | 40 – 70 Bar |
Matching custom tooling configurations to the specific manufacturing sectors flourishing across Turkey's key industrial hubs.
Plastic Injection Mold Cooling Lines: Deep drilling of complex cooling fluid circuits in tool steel (H13, P20, 1.2344) requiring long reach ($>60\times D$) with zero drift to avoid breaching mold cavities.
Naval & Ordnance Machining: Precision deep hole boring of stainless steel valve manifolds, torpedo tubes, high-pressure hydraulic cylinders, and defense artillery barrels requiring tight concentricity.
Powertrain & Fuel Injection Systems: High-volume gundrilling of common rail diesel injectors, transmission shafts, engine block main oil galleries, and steering gear components.
Turkey’s manufacturing footprint is undergoing rapid modernization driven by three primary technological trends:
Combining decades of American cutting tool manufacturing heritage with direct technical support and reliable international delivery to Turkish ports.
Established with over 35 years of specialized grinding experience. Every tool is produced under strict metallurgical control, ensuring lot-to-lot consistency and zero tip detachment during high-stress operations.
We braze application-matched carbide tips: C-2 Class (Grade 883) for superior wear resistance in non-ferrous alloys and cast iron, and C5/C6 Class (Grade 370) for heavy steel cutting and thermal resistance.
Non-standard diameters, special driver shanks (Eldorado, Botek, Whistle Notch, Straight), and step gundrill geometries manufactured to your drawing prints with fast dispatch via Istanbul Airport customs hubs.
Direct engineering answers to technical queries frequently raised by tooling managers and CNC programmers across Turkey.
Coolant pressure depends on the drill diameter. For micro-bores ($\varnothing 1.0\text{mm} – 4.0\text{mm}$), pressures between $70\text{ and }120\text{ bar}$ ($1000–1750\text{ PSI}$) are necessary to push chips out of the long channel. For larger diameters ($\varnothing 12\text{mm}–25\text{mm}$), $20–40\text{ bar}$ is sufficient provided high volumetric coolant flow rate ($\text{L/min}$) is maintained.
On standard CNC machining centers without guide bushings, you must drill a pilot hole first using a short pilot drill or pilot gundrill. The pilot hole should be $+0.005\text{ to }+0.02\text{mm}$ larger than the main gundrill diameter and $2\times D$ deep. The gundrill enters the pilot hole at low speed ($50\text{ RPM}$) without coolant, seats inside, and then engages full speed and coolant pressure before feeding.
Yes. The gundrill tip geometry features a inner angle, outer angle, and apex point ground on the outer nose. Most precision tool grinding shops in İkitelli OSB or Kocaeli equipped with 5-axis CNC tool grinders can resharpen the nose geometry multiple times without reducing the outer diameter, significantly lowering tool cost per part.
Standard catalog items ship within 24–48 hours. Custom engineered gundrills featuring special intermediate diameters, extended length-to-diameter ratios, or tailored step profiles are manufactured and dispatched within 2 to 3 weeks via express air freight directly to your factory door in Turkey.
Solid carbide gundrills are recommended for diameters under $12\text{mm}$ due to superior torsional rigidity and tool life. For diameters above $12\text{mm}$ up to $40\text{mm}+$, carbide-tipped gundrills (which braze a premium grade carbide tip onto a tough alloy steel shank) offer far greater shock absorption against interrupted cuts while remaining significantly more cost-effective.