Gold Plated Tungsten Price

Tungsten Carbide Milling Cutter’s Climb Milling and Up Milling Comparison

Details: Category: Tungsten Information; Published on Wednesday, 29 October 2014 18:21; Written by xjq; Hits: 513

Tungsten carbide milling cutter climb milling has smaller power consumption than up milling. Under the same cutting conditions, climb milling is 5%～15% lower than up milling in power consumption, and also, it can conduct chip removal more easily. In order to improve surface finish of work pieces and ensure size precision, climb milling should be adopted preferentially. However, when there is obvious hardened layer, deposition and uneven work piece surface, up milling should be taken. During climb milling, the cutting thickness is getting thinner and the cutter teeth cut from the unprocessed surface, which is good for the use of tungsten carbide milling cutters. While during up milling, when the cutter teeth touch the work piece, they can not cut into the metal layer immediately, instead, the cutter has to glide a short distance on work piece surface, during which, due to the friction, a great amount of heat will be generated and then form a hardened layer on the surface. ALL these will have bad effects on the cutting, such as reducing the cutter’s service life and lowering the work piece surface finish. In addition, cutter teeth move upwards in up milling and begin with the surface hardened layer, so the teeth will suffer from great impact load, which will make the cutter go blunt quickly.

Because the cutting thickness difference between tungsten carbide milling cutter’s climb milling and up milling, cutters with different milling ways have different wear degrees. Cutters are two to three times more durable in climb milling than in up milling. However, climb milling is not suitable for the milling of work pieces with hard cover.

Tungsten Carbide Milling Cutter’s Climb Milling and Up Milling Comparison

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Tungsten Carbide Milling Cutters' Milling Ways

Details: Category: Tungsten Information; Published on Wednesday, 29 October 2014 18:18; Written by xjq; Hits: 518

Tungsten carbide milling cutter has two main milling ways based on its feeding direction towards the work piece and its rotating direction:

I. Climb milling

During clime milling, the cutter rotating direction is the same as the feeding direction, and therefore when the cutting starts, the cutter soon bites the work piece and cut chip from it.

II. Up milling

During up milling, the cutter rotating direction is contrary to the feeding direction, so before the cutting starts, the cutter has to glide on the work piece with a zero cutting thickness at the beginning and a maximum thickness at the end.

During climb milling, the cutting force presses the work piece to the workbench while during up climb milling makes the work piece leave the work bench. Due to its good cutting effect, climb milling is usually more preferred than up milling. Only when there are thread backlash problem and other problems which can not be solved by climb milling, up milling is then in the consideration.

Whenever tungsten carbide milling cutters get into work, the cutting edges always have to suffer from impact load, the magnitude of which depends on the chip cross section, work piece materials and cutting types. Under ideal conditions, the cutter diameter should be larger than the work piece width and the cutter axial lead should always keep a distance from the work piece center line. When the cutter is placed right against the cutting center, burrs are easily produced. Also, the radial cutting force direction may change continuously when the cutting edge begins or stops cutting, which is possible to cause machine tool spindle vibration and damage. But when tungsten carbide milling cutter keep a small distance from the center, the cutting force direction will not change anymore and the cutter will gain a preliminary load.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com

Tel.: 86 592 5129696; Fax: 86 592 5129797

Email: sales@chinatungsten.com

Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com

Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com

Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Counterfeit Gold-Plated Tungsten Bar-1

Details: Category: Tungsten Information; Published on Wednesday, 29 October 2014 08:50; Written by Sherry; Hits: 524

The following article is talking about the story of counterfeit gold-plated tungsten bar, written by unknow person.

In his March 2 column, he told about the news story where an employee at the world’s largest private refinery had discovered a gold-plated 500 gram gold bar received from an unidentified bank. His column included an internet link where readers could themselves view the German television station report.

As is common for his columns, this particular one was picked up by several other websites. This particular column inspired a relatively harsh response from Robert Bradshaw. In an essay Robert wrote that was posted yesterday at http://www.marketoracle.co.uk/Article17820.html, Robert took me to task for repeating the story that China’s central bank last year had received at least four counterfeit gold-plated 400 ounce tungsten bars. Robert seemed concerned that he was perpetuating a myth about a massive number of counterfeit gold-plated 400 ounce tungsten bars that were supposedly manufactured during the 1990′s at the behest of the US government. Allegedly, about half of them were shipped to Fort Knox.

Until today’s column, he have never referred to the rumor of large numbers of counterfeit gold bars supposedly stored at Fort Knox. he is well aware of the details of this rumor but, like Bradshaw, the possibility of the whole story being true is pretty far-fetched. He would need to dig up more hard confirmation of its veracity before discussing it. If such verification were available, I’m sure that this story would be headline news in the mainstream financial press.

The precious metals markets are not transparent. To get the best idea of what is really happening means listening to sources that often cannot be independently double-checked. In his writings, he tries to be careful to listen only to those sources that have developed a track record of reliability. In this manner, he can often discern the truth long before it is publicly disclosed.

gold-plated-tungsten-bar

Tungsten Alloy Manufacturer & Supplier: Chinatungsten Online - http://www.tungsten-alloy.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Tungsten News & Tungsten Prices, WML Version: http://m.chinatungsten.com

Tungsten Carbide Cutting Tool Coating Technology Introduction

Details: Category: Tungsten Information; Published on Wednesday, 29 October 2014 18:16; Written by xjq; Hits: 541

During machining, the cutting tool property has decisive impact on the cutting efficiency, precision, and surface quality. Two essential dictators of tungsten carbide tool property are hardness and intensity, which, however, are always contradictory to each other. Materials with high hardness are often at the expense of their intensity, while increased intensity always results in decreased hardness. In order to settle this kind of contradiction and improve cutting tool property, one effective solution is by taking coating technology. Coatings are materials put on the surface of tungsten carbide cutting tools through coating technology and they are of high hardness and high abrasion resistance. The tungsten carbide cutting tool coating, like a chemical and thermal barrier, can reduce crater wear of the tools and thus significantly improve machining efficiency and precision, extend tool life and reduce cost.

Tungsten carbide cutting tool coatings help improve tool's abrasion resistance but at the same time maintain tool intensity and reduce friction between tools and work pieces, so the tool life is thus extended. In addition, because the coefficient of heat conduction of coatings is much lower than that of tools and materials being processed, it can contribute to reducing heat caused by friction. It forms a thermal barrier and change the ways of heat lost, and thus reducing the thermal and force impact from the friction and effectively improve the tool property.

Main functions of tungsten carbide cutting tool coatings are as follows:

I. To form a isolated layer between tools and materials being processed.

II. To reduce thermal impact through inhibiting heat conduction from cutting area to blades.

III. To effectively reduce friction and heat caused by friction.

Tungsten Manufacturer & Supplier: Chinatungsten Online - http://www.chinatungsten.com
Tel.: 86 592 5129696; Fax: 86 592 5129797
Email: sales@chinatungsten.com
Tungsten & Molybdenum Information Bank: http://i.chinatungsten.com
Tungsten News & Tungsten Prices, 3G Version: http://3g.chinatungsten.com
Molybdenum News & Molybdenum Price: http://news.molybdenum.com.cn

Tungsten Carbide Keyway Broach Introduction

Details: Category: Tungsten Information; Published on Tuesday, 28 October 2014 18:01; Written by xjq; Hits: 522

Tungsten carbide keyway broach, as its name implies, is a kind of cutter using for splining.

Types of keyway:

Woodruff keyway has the same keyway size and limit deviation with flat key keyway. Therefore, the tungsten carbide keyway broach can be used in both of them.

Taper key keyway is 0.5~1.3mm shallower than flat key keyway. The groove depth of guide sleeve should be increased if the standard keyway broach is used in splining taper key keyway at one time. But if it is doing for many times (b≥14mm), then the gasket thickness should be calculated again.

Thin flat key keyway is 0.9~3.5mm shallower than flat key keyway, and the groove depth of guide sleeve during splining at one time should be chosen based on the guide sleeve size a. But if it is doing for many times, proper gasket thickness should be selected.

The characteristics of tungsten carbide keyway broach:

I. It has large broaching allowance and teeth number, therefore if the groove is quite deep, then the splining should be done by two times.

II. The broaching surface roughness is relatively high (Ra 2.5~1.25 μm or even higher). When low surface roughness is required, keyway broach with lateral wiper should be adopted.

III. When the guide sleeve is not long enough, the broach may bend upwards and even break during operation.

IV. Edge-line of teeth with enough width should be guaranteed in order to increase broaching stability.