The History of Dartboard
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- Category: Tungsten Information
- Published on Monday, 02 February 2015 09:47
- Written by xsh
- Hits: 467
The dartboard may have its origins in the cross-section of a tree. An old name for a dartboard is "butt"; the word comes from the French word , but the meaning is "target". In particular, the Yorkshire and Manchester Log End boards are differ from the standard board in that they have no treble, only double and bulls’ eye, the Manchester board being of a smaller diameter, with a playing area of only 25 cm across with double and bull areas measuring just 4mm. The London Fives board is another variation. This has only 12 equal segments numbered 20, 5, 15, 10, 20, 5, 15, 10, 20, 5, 15, 10 with the doubles and triples being a quarter of an inch wide.
There is a speculation that the game originated among soldiers throwing short arrows at the bottom of the cask or at the bottom of trunks of trees. As the wood dried, cracks would develop, creating "sections". Soon, regional standards emerged and many woodworkers supplemented bar tabs by fabricating dart boards for the local pubs.
The standard numbering plan with a 20 on top was created in 1896 by Lancashire carpenter Brian Gamlin. However, a great many other configurations have been used throughout the years and in different geographical locations. Gamlin's layout was devised to penalize inaccuracy. Although the most of the boards, the left-hand side (near the 14 section) is preferred by beginners, for its concentration of larger numbers. Mathematically, removing the rotational symmetry by placing the "20" at the top, there are 19!, or 121,645,100,408,832,000 possible dartboards. Many different layouts would penalize a player more than the current setup, however, the current setup actually does the job rather efficiently. There have been several mathematical papers published that consider the "optimal" dartboard.
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MSDS of Tungsten Bar(a)
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- Category: Tungsten Information
- Published on Monday, 02 February 2015 09:45
- Written by Sherry
- Hits: 663
CHEMICAL NAME: |
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Trade Name and Synonyms: All CHINATUNGSTEN ONLINE’S TUNGSTEN PRODUCTS |
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Chemical Family: Refractory Metal Tungsten |
Molecular Weight : N/A |
PHYSICAL DATA |
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Appearance and Odor: Dark Gray Metal/No Odor |
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Boiling Point: 5927℃ |
Specific Gravity (H20=1): 11.0 to 15.5 |
Vapor Pressure (mm Hg): N/A |
Percentage Volatile by Volume: 0 |
Vapor Density (Air=1): N/A |
Evaporation Rate: N/A |
Solubility in Water: Insoluble |
How Best Monitored: Air Sample |
HAZARDOUS INGREDIENTS |
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Material |
% by Weight |
OSHA PEL |
ACGIH TLV |
Tungsten Carbide (limits Tungsten dust) |
41-97%* |
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5 mg/m 3 |
Cobalt and other elements |
3-10% * |
0.1 mg/m3 |
0.1 mg/m3 |
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Which Tungsten Dart Weight Is Best?
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- Category: Tungsten Information
- Published on Friday, 30 January 2015 16:46
- Written by xsh
- Hits: 501
Choosing weight of dart to use can be tricky and it is would be trial and error again and again. Basically a heavier Tungsten dart will suit a more relaxed throw, while a lighter dart would suit some one who wants to put more effort in. Ladies will choose a heavier dart to get more power, but this is not always for it.
Steel Tip Dart Weights
Range 18gm to 32gm.
Most common 23gm and 24gm - ideal for beginners
Soft Tip Dart Weights
Traditionally range 14gms to 20gms
Heavier weight now introduced up to 25gms
Most common 18gm - ideal for beginners.
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How Much Tungsten in The Darts?
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- Category: Tungsten Information
- Published on Friday, 30 January 2015 17:34
- Written by xsh
- Hits: 504
Tungsten darts come in many different varieties and percentages. You will see the most common being 70%, which usually means 70% tungsten, 30% nickel.
Sometimes mixed with copper for sets, however those are unusual to find . You can find darts with a trace of tungsten up to about 98% tungsten in the more expensive sets.
Remember that the more tungsten you buy, the darts will hold up better, last longer, and be thinner, which will help your shooting.
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Tungsten Blue Oxides
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- Category: Tungsten Information
- Published on Friday, 30 January 2015 16:42
- Written by cq
- Hits: 440
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