Grains (gr) to Tons (t) conversion

What is the Grain?

The grain is a small unit of mass in the avoirdupois, troy, and apothecaries' systems. Today it is used mainly for bullets, gunpowder, arrows, and some medications.

Definition

The grain is defined as exactly 1/7000 of an avoirdupois pound:

$$1\ \text{gr} = 6.47989 \times 10⁻⁵\ \text{kg}$$

Precisely, 1 grain = 64.79891 mg exactly. There are 7000 grains in an avoirdupois pound and 480 grains in a troy ounce, making the grain the common link between the troy, avoirdupois, and apothecaries' systems.

Origin and History

The grain originally referred to the mass of a single seed of a cereal grain such as wheat or barley. It is one of the oldest units of mass in the English-speaking world and long served as the base unit from which pounds and ounces were built.

Law and Notable Facts

The grain is the only mass unit shared identically across the troy, avoirdupois, and apothecaries' systems. In firearms, ammunition is still specified in grains—for both projectile mass and powder charge.

Real-World Examples and Conversions

A common 9mm bullet weighs about 115 grains (≈7.45 g). A standard aspirin tablet of 325 mg is roughly 5 grains. One gram equals about 15.43 grains.

What is Tons?

Tons are a unit of mass, primarily used for measuring heavy objects. However, there are different types of tons, each with a slightly different weight. The most common are the metric ton, the short ton (or US ton), and the long ton (or UK ton). This document aims to give more insights for each of the ton measure.

Types of Tons

• Metric Ton (tonne): The metric ton, also known as a tonne, is defined as 1,000 kilograms.
• Short Ton (US Ton): The short ton, or US ton, is defined as 2,000 pounds.
• Long Ton (UK Ton or Imperial Ton): The long ton, also known as the UK ton or imperial ton, is defined as 2,240 pounds.

Conversion Between Tons

Here's how to convert between the different types of tons:

• 1 metric ton = 1,000 kg ≈ 2,204.62 lbs ≈ 1.102 short tons ≈ 0.984 long tons
• 1 short ton = 2,000 lbs ≈ 907.185 kg ≈ 0.907 metric tons ≈ 0.893 long tons
• 1 long ton = 2,240 lbs ≈ 1,016.05 kg ≈ 1.016 metric tons ≈ 1.12 short tons

$$1 \text{ metric ton } = 1000 \text{ kg}$$

$$1 \text{ short ton } = 2000 \text{ lbs}$$

$$1 \text{ long ton } = 2240 \text{ lbs}$$

Origin and History

The term "ton" has its roots in the Old English word "tun," which referred to a large cask or barrel. Over time, it evolved to represent a unit of weight based on the capacity of such a barrel, typically used for wine or other goods. The different types of tons arose due to variations in measurement systems between countries and industries.

Real-World Examples

• Shipping: Cargo ships often measure their carrying capacity in metric tons.
• Mining: The extraction and trade of ores, like iron ore, are frequently quantified in metric tons.
• Construction: Materials like concrete and steel are often ordered and priced by the ton.
• Agriculture: Crop yields, such as wheat or corn, can be measured in tons, especially on a large scale.
• Waste Management: Municipal waste and recycling amounts are often reported in tons.

Interesting Facts

• The metric ton is part of the International System of Units (SI).
• The term "tonnage" is often used in the shipping industry to refer to a vessel's cargo-carrying capacity, although it doesn't always directly correspond to weight in tons. Instead, it can relate to volume or other measures.
• The abbreviation for metric ton is "t," while short ton is often abbreviated as "ST" and long ton as "LT" to avoid confusion.

Notable Associations

While no specific law or person is directly associated with the ton as a unit of measurement, its use is deeply embedded in various industries and regulations related to trade, transportation, and commerce. For example, international trade agreements often specify quantities of goods in metric tons.