Hemming and seaming

Hemming and seaming are two similar metalworking processes in which a sheet metal edge is rolled over onto itself. Hemming is the process in which the edge is rolled flush to itself, while a seam joins the edges of two materials.

Hems are commonly used to reinforce an edge, hide burrs and rough edges, and improve appearance.

Seams are commonly used in the food industry on canned goods, on amusement park cars, and in the automotive industry.

Process

The process for both hemming and seaming are the same, except that the tonnage requirement is greater for seaming. The process starts by bending the edge to an acute angle. A flattening die is then used to flatten the hem.

Types

There are two types of hemmed edges: closed hems and open hems. Closed hems are completely flush while open hems have an air pocket in the bend. The major difference is that the tonnage required for a closed hem is much greater than that for an open hem.

See also

References

Bibliography

Seam (sewing)

In sewing, a seam is the join where two or more layers of fabric, leather, or other materials are held together with stitches. Prior to the invention of the sewing machine, all sewing was done by hand. Seams in modern mass-produced household textiles, sporting goods, and ready-to-wear clothing are sewn by computerized machines, while home shoemaking, dressmaking, quilting, crafts, haute couture and tailoring may use a combination of hand and machine sewing.

In clothing construction, seams are classified by their type (plain, lapped, abutted, or French seams) and position in the finished garment (center back seam, inseam, side seam). Seams are finished with a variety of techniques to prevent raveling of raw fabric edges and to neaten the inside of garments.

Types

All basics seams used in clothing construction are variants on four basic types of seams:

A plain seam is the most common type of machine-sewn seam. It joins two pieces of fabric together face-to-face by sewing through both pieces, leaving a seam allowance with raw edges inside the work. The seam allowance usually requires some sort of seam finish to prevent raveling.

Stratum

In geology and related fields, a stratum (plural: strata) is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers. The "stratum" is the fundamental unit in a stratigraphic column and forms the basis of the study of stratigraphy.

Characteristics

Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural processes. They may extend over hundreds of thousands of square kilometers of the Earth's surface. Strata are typically seen as bands of different colored or differently structured material exposed in cliffs, road cuts, quarries, and river banks. Individual bands may vary in thickness from a few millimeters to a kilometer or more. Each band represents a specific mode of deposition: river silt, beach sand, coal swamp, sand dune, lava bed, etc.

Naming

Geologists study rock strata and categorize them by the material of beds. Each distinct layer is typically assigned to the name of sheet, usually based on a town, river, mountain, or region where the formation is exposed and available for study. For example, the Burgess Shale is a thick exposure of dark, occasionally fossiliferous, shale exposed high in the Canadian Rockies near Burgess Pass. Slight distinctions in material in a formation may be described as "members" (or sometimes "beds"). Formations are collected into "groups" while groups may be collected into "supergroups".

Tarì

A tarì (طري lit. "fresh" or "newly minted money" in Arabic) was the Christian designation of a type of gold coin of Islamic origin minted in Sicily, Malta and Southern Italy from about 913 to 1859.

History

In the Islamic world, this type of coin was designated under the name ruba'i, or quarter-dinar, as it weighed 1.05g of gold. The ruba'i had been minted by the Muslims in Sicily, unlike the Muslim rulers of North Africa, who preferred the larger dinar. It became highly popular as it was smaller and therefore more convenient than the large-sized 4.25g dinar.

The tarì were so widespread that imitations were made in southern Italy (Amalfi and Salerno) from the mid-tenth century, which only used illegible "pseudo-Kufic" imitations of Arabic. When the Normans invaded Sicily in the 12th century, they issued tarì coins bearing legends in Arabic and Latin.Roger II of Sicily issued such coins, becoming the only Western ruler at that time to mint gold coins. Their title was 16¹⁄₃ carat, with some adjunction of silver and copper. The tarì were also produced by the Hohenstaufens and the early Angevins.

The Color of Time

The Color of Time (aka Tar) is a 2012 drama film written and directed by twelve New York University film students: Edna Luise Biesold, Sarah-Violet Bliss, Gabrielle Demeestere, Alexis Gambis, Shruti Ganguly, Brooke Goldfinch, Shripriya Mahesh, Pamela Romanowsky, Bruce Thierry Cheung, Tine Thomasen, Virginia Urreiztieta and Omar Zúñiga Hidalgo. It stars James Franco, Henry Hopper, Mila Kunis, Jessica Chastain and Zach Braff. It premiered on November 16, 2012 at the Rome Film Festival. It was released in the United Kingdom in 2014 under the new title Forever Love. The film was released in the United States in theaters and on demand beginning on December 12, 2014.

Plot

The different parts of Pulitzer Prize winner C.K. Williams' life told through his poems. Flashbacks of his childhood, his teens, college years, to when he meets and marries his wife, Catherine (Kunis) and the birth of his children and parenthood. The film is narrated by different versions of Williams (Franco, Hopper, March, Unger), depicting the different aspects of Williams through the years.

Tar (disambiguation)

Tar is a viscous organic black liquid.

Tar or TAR may also refer to:

Other common meanings

In medicine

Music