Auger-shaped single-point fastener attaches rigid surface insulation tiles to orbiter shuttle spacecraft. Method can be used to bond wide variety of materials, including insulation, elastomers, and fibrous materials. Since insulation is attached at only one point, insulation and structure are free to form without inducing bond separation

Schneider, W. C.

English

NASA Technical Reports Server

January 1975	 B74-10269 
NASA TECH BRIEF 
Lyndon B. Johnson Space Center 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
New Insulation Attachment Method Eliminates Compatibility Bondline Stresses 
Single-Point Fastener 
The problem: 
Adhesive bonding, rather than rivets or similar 
fasteners, is frequently used to mount insulation or 
other low-shear-strength materials. However, if 
adhesive bonding is used and the system is subjected 
to thermal and/or mechanical stresses, bond separa-
tion in the insulation may occur. 
The solution: 
An auger-shaped single-point fastener was dev-
eloped to attach rigid surface insulation tiles to the 
orbiter shuttle spacecraft. This same method can be 
used in industry to bond a wide variety of materials, 
including insulation, elastomers, and fibrous mat-
erials.
How It's done: 
The auger attachment fixture is shown in the 
illustration. Since the insulation is attached at only 
one point, the insulation and the structure are free to 
form without inducing bond separation, as might 
occur with adhesive bonding. The auger has a large 
shear and a large bearing area; thus, it may be used 
with relatively low-strength materials which could not 
be suitably attached by other means. 
An attachment screw is fitted in the hollow stem of 
the auger. The screw is held in place by Belleville 
springs and an insulating washer. To mount an 
insulation tile, two holes are first drilled in it. One, 
the diameter of the auger stem, serves as a recess for 
the auger, and the second is a smaller-diameter tool 
hole.
(continued overleaf) 
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I 
The auger is screwed into the insulation with a 
special tool that is secured by the attachment screw. 
After the auger is screwed into the tile, the tool may be 
removed by loosening the attachment screw via the 
tool hole. An attachment hole is then drilled in the 
surface of the structure to which the tile is to be 
attached. 
A fibrous pad is placed over the surface of the 
structure and the tile is installed by inserting the 
adjusting screw through the hole in the surface of the 
structure. A blind end fastener is used to secure the 
tile. The auger is then tightened with the adjustment 
screw.
Note: 
Requests for further information may be directed 
to:
Technology Utilization Officer 
Johnson Space Center 
Code AT3 
Houston, Texas 77058 
Reference: TSP74-10269 
Patent status: 
This invention is owned by NASA, and a patent 
application has been filed. Inquiries concerning 
nonexclusive or exclusive license for its commercial 
development should be addressed to: 
Patent Counsel 
Johnson Space Center 
Code AM 
Houston, Texas 77058 
Source: W. C. Schneider
Johnson Space Center 
(MSC-12615) 
B74-10269	 Category: 07 (Machinery)


New insulation attachment method eliminates compatibility bondline stresses

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