Login Form


Ultralights can be safe, sun and air vehicles if built and flown with safety in mind. Because of their very nature, they are designed within very close tolerances to remain strong and safe. Leading Edge Air Foils (LEAF) Inc. of Colorado has found that some pilots and ultralight builders are substituting lower grade bolts than specified in their projects. The manufacturers of these bolts cut costs by using cheaper grades of steel and heat treating at lower than specified temperatures.

LEAF is urging all homebuilders to examine bolts purchased recently. Be wary, LEAF warns, of grade 5 and grade 8 fasteners of foreign origin that do not have a letter indicating the manufacturer. Also, eliminate from your hardware inventory any grade 8 head marks with the following letters:

A -- Asohi Manufacturing, Japan.

E -- Daici, Japan.

FM -- Fastener Company of Japan.

H -- Hinomoto Metal, Japan.

hollow triangle -- Infasco

J -- Jinn Her, Taiwan.

KS -- Kosaka Kogyo, Japan.

KY -- Kyoei Manufacturing, Japan.

M -- Minamida Sicybo, Japan.

MS -- Minato Kogyo, Japan

NF -- Hinomoto Metal, Japan.

RT -- Takai Ltd., Japan.

UNY -- Unytite, Japan.

Before you fly, if you have any questions about the bolts you're using, contact Leading Edge Air Foils, 331 S. 14th St., Dept. US, Colorado Springs, CO 80904-4096; phone: (719) 632-4959; FAX: (719) 632-2815.

You can order a PDF or printed copy of Q-talk #29 by using the Q-talk Back Issue Order Page.