<s>
Direct	B-Algorithm
tension	I-Algorithm
indicators	I-Algorithm
,	O
or	O
DTIs	O
,	O
are	O
single-use	O
mechanical	O
load	B-Algorithm
cells	I-Algorithm
used	O
to	O
indicate	O
when	O
the	O
required	O
tension	O
has	O
been	O
achieved	O
in	O
structural	O
fastener	O
assemblies	O
.	O
</s>
<s>
The	O
standard	O
for	O
DTIs	O
in	O
North	O
America	O
is	O
the	O
ASTM	O
International	O
series	O
of	O
standards	O
and	O
the	O
specific	O
designation	O
for	O
testing	O
and	O
manufacturing	O
DTIs	O
is	O
ASTM	O
F959	O
:	O
Standard	O
Specification	O
for	O
Compressible-Washer	O
Type	O
Direct	B-Algorithm
Tension	I-Algorithm
Indicators	I-Algorithm
for	O
Use	O
with	O
Structural	O
Fasteners	O
.	O
</s>
<s>
DTIs	O
within	O
the	O
RCSC	O
specification	O
section	O
8.2.4	O
are	O
described	O
thus	O
:	O
"	O
ASTM	O
F959	O
direct	B-Algorithm
tension	I-Algorithm
indicators	I-Algorithm
are	O
recognized	O
in	O
this	O
Specification	O
as	O
a	O
bolt-tension-indicating	O
device	O
.	O
</s>
<s>
Direct	B-Algorithm
tension	I-Algorithm
indicators	I-Algorithm
are	O
hardened	O
washer	O
shaped	O
devices	O
incorporating	O
small	O
arch-like	O
protrusions	O
on	O
the	O
bearing	O
surface	O
that	O
are	O
designed	O
to	O
deform	O
in	O
a	O
controlled	O
manner	O
when	O
subjected	O
to	O
compressive	O
load.	O
"	O
</s>
<s>
Steel	O
materials	O
used	O
in	O
the	O
manufacture	O
of	O
direct	B-Algorithm
tension	I-Algorithm
indicators	I-Algorithm
shall	O
be	O
designed	O
,	O
processed	O
,	O
heat	O
treated	O
,	O
and	O
protectively	O
coated	O
as	O
specified	O
.	O
</s>
<s>
The	O
direct	B-Algorithm
tension	I-Algorithm
indicators	I-Algorithm
shall	O
conform	O
to	O
required	O
chemical	O
composition	O
,	O
compression	O
load	O
,	O
and	O
dimensional	O
values.	O
"	O
</s>
