Glassary - M

M60:
obsolete tinted interlayer.

Magnetron sputtering:
a technical term to describe the process used in off-line coating. This involves passing the glass into a vacuum chamber. Argon gas is then introduced and electrical currents are then passed into a series of special coating beams in the roof of the chamber. The current causes small amounts of metal oxides to "sputter" onto the glass below and form a thin uniform coating.

Manifestation:
making panes of glass, whose presence may not be immediately obvious, easily visible by the application of permanent patterns, logos or other markings, in order that persons should not walk into them without noticing. This is a requirement of Building Regulations Part N, England and Wales, Part P Scotland and Part V Northern Ireland, which is often not followed. See Technical Bulletin Glass and Safety.

Manual attack:
attack using manually held implements or thrown objects, but not firearms. See Technical Bulletin Glass and Security.

Marked:
having a permanent inscription indicating the performance of the product and other information. The most common marks are those related to safety glass classification, fire performance and to insulating glass unit performance.

Marking:
the permanent inscription marked on the glass.

Mayflower™:
Pilkington Mayflower™ is the brand name for one of the Pilkington Texture Glass™ range (see consumer leaflet Pilkington Texture Glass™) of patterned glass. Pilkington Mayflower™ has an obscuration level of 4.

Mean sound reduction index (Rm):
the average of 16 sound insulation values over the frequency range 100-3150Hz (see acoustic properties).

Metal casement putty:
the traditional glazing compound for single glazed steel windows. Metal casement putty is NOT suitable for insulating units or laminated glass.

M.G.U.:
Multiple glazing unit.

Minster™:
Pilkington Minster™ is the brand name for one of the Pilkington Texture Glass™ range (see consumer leaflet Pilkington Texture Glass™) of patterned glass. Pilkington Minster™ has an obscuration level of 2.

Mirage:
The old brand name for an on line coated one way vision mirror. This is no longer made but Pilkington Mirropane™ (see Product Data Sheet) is the product we now offer as a one way vision mirror.

Mirropane™:
Pilkington Mirropane™ (see Product Data Sheet) is our one-way vision mirror.

Mirror:
a glass, which is highly reflective and opaque. Silvering followed by an application of backing paint form the commonest type of mirror.

Molecular sieve:
another name for desiccant.

Mullion:
a vertical dividing bar between panes of glass in a window or a door.

Multi-laminated:
containing more than two plies of glass in the laminate.

Multi-pane:
a term applied to fire resistant glazing which has been tested with more than one pane of glass in the assembly. It does NOT indicate double windows or insulating glass units.

Multiple glazing unit:
an alternative term for insulating glass unit comprising two or more panes.