Kunshan Meiyaxing Hardware Machinery Co., Ltd. is a direct branch of Hong Kong Meiya International Trading Co., Ltd. in China. It owns its own cutting tool brand: MANF, and engages in the sales and operation services of CNC cutting tools. It provides tungsten carbide end mills, milling inserts, turning inserts, grooving and parting inserts, drilling and boring inserts, multi-functional inserts, threading inserts, and other indexable inserts and their matching tool holders and tool holders. Furthermore, it has established long-term strategic partnerships with many well-known manufacturers, with joint R&D, design, and production teams, advanced equipment, and continuously innovative technical strength. It is committed to mutual cooperation, guided by technical services, forming a mutually supportive industrial chain to solve various processing problems for manufacturing enterprises. In the field of machining, deep hole machining (usually referring to holes with an aspect ratio exceeding 5) has always been a technical challenge. Traditional twist drills often face problems such as difficult chip removal, poor heat dissipation, and drilling deviation in this type of machining. Gun drills... The emergence of deep-hole gun drills has provided a near-perfect solution to this problem. Originally used in gun barrel manufacturing, it is now widely used in precision manufacturing industries such as automotive, aerospace, hydraulics, and mold making. This article will analyze the core advantages of deep-hole gun drills in detail and provide you with key points for scientific selection.
The Disruptive Advantages of Gun Drills Compared to Traditional Twist Drills
The most direct way to understand the value of gun drills is to compare them with common twist drills. This comparison is particularly striking in deep-hole machining scenarios.
How to Scientifically Select Gun Drills and Machining Systems?
While offering significant advantages, gun drills are not a "panacea." Scientific selection requires comprehensive consideration from three dimensions: cutting tools, equipment, and processes.
1. Key Points for Cutting Tool Selection
· Type Selection: For small diameters (e.g., Φ1.5-Φ40mm), welded carbide gun drills are preferred due to their high cost-effectiveness; for large diameters or complex working conditions, solid carbide or indexable insert gun drills can be considered. When machining difficult-to-cut materials (e.g., titanium alloys, stainless steel), it is recommended to use gun drills with wear-resistant coatings such as TiAlN.
· Key geometric parameters: Drill tip geometry directly affects cutting force and chip breaking effect. For example, the outer cutting edge angle (φ_outer) and inner cutting edge angle (φ_inner) need to be adjusted according to the material hardness-a smaller drill tip angle is used for harder materials, and a larger drill tip angle is used for softer materials.
• Staged machining strategy: When the hole depth exceeds 30-40 times the drill bit diameter, staged drilling should be used, that is, multiple drill bits of increasing length should be used sequentially, and appropriate auxiliary supports should be added to prevent the drill rod from vibrating or breaking due to excessive length.
2. Matching of equipment and cooling system
• Equipment conditions: Gun drills are not self-centering; a guide sleeve or pre-drilled guide hole must be used for precise guidance before machining. It can be used on dedicated deep hole drilling machines, as well as machining centers equipped with high-pressure cooling systems, or modified lathes and boring machines.
• A high-pressure cooling system is the lifeline: it's the core of successful gun drill applications. The coolant must possess high pressure (up to 10MPa or higher), high flow rate, and high filtration accuracy (5-10μm). Viscosity must be selected according to pore size; smaller pore sizes require lower viscosity to ensure flow rate. Simultaneously, it is recommended to use a dedicated gun drill oil containing extreme pressure additives to form a lubricating film and prevent dry friction.
3. Operation and Maintenance Standards
• Standard Operating Procedures: Always adhere to the sequence of "turn on the coolant first, then start the spindle, and finally start the feed"; when retracting the tool, turn off the coolant and stop the spindle before retracting.
• Forced regrinding management: Gun drills cannot be manually sharpened on ordinary grinding machines after wear. They must be regrinded with diamond wheels on a dedicated grinding machine to maintain the original geometry. Otherwise, machining accuracy and lifespan will be significantly affected.
Deep hole gun drills, with their unique single-edge guide and internal cooling with external chip removal design, have overturned the efficiency and accuracy ceiling of traditional deep hole machining. When selecting a gun drill, please abandon the "general-purpose tool" mentality and instead systematically select the tool type, match the high-pressure cooling system, and follow strict process specifications based on the part material, hole diameter accuracy, hole depth-to-diameter ratio, and existing equipment conditions. For deep hole machining scenarios that demand high precision and high efficiency, gun drills are a highly valuable investment.
If you have any questions about MANF brand tools, please call us for consultation or negotiation"
Contact us:Company name:Kunshan Meiyaxing Hardware Machinery Co., Ltd;Tel:8618962438699;Address: Room 3003, Building 3, Zhengtailong, No. 1288 Chengbei Middle Road, Kunshan City, Jiangsu Province, China;Email:myxcuttingtools@gmail.com;Website: https://www.myxcuttingtools.com
