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Archive for August, 2018

Katy Spring & Manufacturing Benefits:

Tuesday, August 28th, 2018

  • No automatic expedite fees
  • Volume-discounted pricing structure
  • A one-order-at-a time quality and service philosophy
  • Flexible lead times
  • Advanced change-in-schedule notification
  • Long-term and stocking agreement programs offered for some projects
  • Diversified customer and market base
  • Advanced spring-manufacturing technology
  • 75 combined years of spring design assistance
  • Owned by 3 generations of spring makers
  • Customer service training throughout the entire organization
  • 50,000 square feet of space on 20 acres, owned by Katy Spring shareholders
  • Warranty and guarantee in writing.

For more information contact call  281-391-1888  or visit our website

Extension Spring Design

Tuesday, August 28th, 2018

Helical extension springs exert a force by pulling or stretching them.  Usually, they are made from round wire and are close-wound with the initial tension between the coils.  Their ends can be formed with loops in many varieties to attach to their applications.


Extension Springs .040 Zin plated music wire extension for marine products

Extension Springs .040 Zin plated music wire extension for marine products


Material data sheet:

Common Spring Materials

Recommended %



Music Wire



Chrome Silicon



Chrome Vanadium



302 Stainless Steel



316 Stainless Steel



17-7 Stainless Steel




The following tables give tolerances that can be used as a reference.  Actual manufacturing tolerances will depend on the spring specifics.


Outside Diameter Tolerances:



Spring Index, D/d




     8            10           12




0.002 0.002 0.003 0.004 0.005 0.006 0.007


0.002 0.003 0.004 0.006 0.007 0.008



0.002 0.004 0.006 0.007 0.009 0.011 0.013


0.003 0.005 0.007


0.012 0.015 0.017


0.004 0.007


0.013 0.016 0.019 0.022


0.006 0.009 0.013 0.018 0.021 0.025 0.029


0.008 0.012 0.017 0.023 0.028 0.033 0.038


0.011 0.015 0.021 0.028 0.035 0.042 0.049




0.026 0.037 0.046 0.054 0.064











Spring Free Length Tolerances

.5 in or less


0.5″ to 1.0″


1″ to 2.0″


2″ to 4″


4″ to 8″


8″ to 16″


16″ to 24″


Stainless Steel Wire Springs

Thursday, August 23rd, 2018




Wire Type


Nominal Analysis

Modulus of Elasticity E

Modulus in Torsion

Max Operating Temp. F

Rockwell Hardness
Stainless Steel Wire AISI 302/304 ASTM A 313 Cr 17.-19.% Ni 8.-10.% 28 (193) 10 (69.0) 550 C35-45
AISI 316 ASTM A 313 Cr 16.-18% Ni 10.-14.% Mo 2.-3.% 28 (193) 10 (69.0) 550 C35-45
17-7 PH ASTM A 313 (631) Cr 16.-18.% Ni 10.-14.% Al 0.75-1.5% 29.5 (203) 11 (78.5) 650 C38-57
  • AISI 302/304 Stainless Steel Wire Springs

    – This is the most popular stainless steel alloy for springs, exhibiting good tensile strength, high corrosion resistance, good heat resistance, and slight magnetic properties. It maintains its strength at temperatures up to 550 degrees F. 302/304 is cold drawn and meets ASTM A 313 standards.

  • AISI 316 Stainless Steel Wire Springs

    – 316 stainless steel wire exhibits better corrosion resistance than 302/304 alloy wire, though it has less tensile strength. It has superior cold forming properties and exhibits short term tensile and creep strength at temperatures up to 550 degrees F. It is used for springs in corrosive environments that do not require high impact or load strength. It meets ASTM A 313 standards.

  • 17-7 PH (AISI 631) Stainless Steel Springs

    – An excellent material for all types of spring applications, 17-7 stainless steel wire offers long life under extreme conditions. It exhibits superior fatigue properties, elasticity, strength-to-weight ration, high yield strength, ductility, and good corrosion resistance, at temperatures up to 650 degrees F.   It meets ASTM A 313 standards.

Long Compression Springs | Extra Long Compression Springs

Wednesday, August 22nd, 2018

Seeking Long Compression Springs or Extra Long Compression Springs?    Contact Katy Spring Phone: 281-391-1888  or visit our website:

Long Compression Springs

Long Compression Springs

Compression Spring terms:

Wednesday, August 22nd, 2018


stainless steel compression springs

stainless steel compression springs

Compression Spring terms:


Active Coils- the coils that deflect when a compression spring is under load.

Buckling the point at which a compression spring bends when a long, slender compression spring is under load.

Closed Ends- the point at the end of a compression spring where the end coils touch.

Closed and Ground End- same as closed ends except the ends of the compression spring is ground flat.

Closed Wound- the state in which a compression spring is coiled with all adjacent coils touching.

Deflection- motion of the compression spring when placed under load.

Elastic limit- the maximum amount that compression spring wire can be placed under load before the compression spring sets.

Endurance limit- the maximum compression spring material can operate indefinitely without failure during minimum stress.

Free length- the overall length of a compression spring under no load.

Frequency- the lowest rate of vibration for a compression spring while ends are held stationary.

Hysteresis- the amount of energy lost in a compression spring during cycling.

Mean diameter- the outside diameter of a compression spring minus one wire diameter.

Modulus- the coefficient in stiffness of a compression spring.

Open ends- the same pitch throughout a compression spring

Open ends ground- same as open ends but with ground ends

Permanent set- when a compression spring is deflected beyond its elastic limit as does not return to its original position.

Pitch- the distance of one wire mean to the adjacent wire mean in a compression spring.

Rate- the change in compression spring load between units of measure.

Set removal- compressing a compression spring to its solid height to achieve desired length and reduce elastic limit.

Set- permanent distortion caused by compressing a compression spring beyond its elastic limit.

Slenderness ration- ratio of length to mean diameter in a compression spring.

Solid height- the position of a compression spring when compressed, all adjacent coils are touching.

Spring Index- the ratio of mean coil diameter to wire diameter in a compression spring.

Squareness- the angular difference between a compression spring axis and plane ends.

Total coils- the number of active coils plus the inactive compression spring coils.

The History of Watch Springs

Tuesday, August 14th, 2018

The history of companies is built by many short stories; some boring, some not. We’re going to try and tell the not-so-boring ones (in our humble opinion) about Katy Spring & Mfg., Inc.; a company in Katy Texas that started with a conversation that ended something like this; “Why not.”

These are the stories about Katy Spring, small bits of a bigger story that started in 1999. The stories are still unfolding new chapters every day, thanks to our wonderful customers. It’s written for our customers and future customers so that they can get to know our company, our employees, some historical background and philosophy a little better.

The stories are not told in chronological order. This blog is more of a “Readers Digest” about Katy Spring, written in whatever random order they appear. So, without further ado, let’s get started with the next read which is titled; “The History Watch Springs”

Mainsprings appeared in the first spring powered clocks, in 15th century Europe. It replaced the weight hanging from a cord wrapped around a pulley, which was the power source used in all previous mechanical clocks. Around 1400 coiled springs began to be used in locks, and many early clockmakers were also locksmiths. Springs were applied to clocks to make them smaller and more portable than previous weight driven clocks, evolving into the first pocket watches by 1600. Many sources erroneously credit the invention of the mainspring to the Nuremberg clockmaker Peter Henlein.  However, many references in 15th century sources to portable clocks ‘without weights’, and at least two surviving examples, show that spring driven clocks existed by the early years of that century.

The first mainsprings were made of steel without tempering or hardening processes. They didn’t run very long, and had to be wound twice a day. Henlein was noted for making watches that would run 40 hours between windings. The modern watch mainspring is a long strip of hardened and blued steel, or specialized steel alloy, 20–30 cm long and 0.05-0.2 mm thick. The mainspring in the common 1-day movement is calculated to enable the watch to run for 36 to 40 hours, i.e. 24 hours between daily windings with a power-reserve of 12 to 16 hours, in case the owner is late winding the watch. This is the normal standard for hand-wound as well as self-winding watched, used in clocks meant to be wound weekly, provide power for at least 192 hours but use longer mainsprings and bigger barrels.  Lock mainsprings are similar to watch springs, only larger.

Since 1945, carbon steel alloys have been increasingly superseded by newer special alloys (iron, nickel and chromium with the addition of cobalt, molybdenum, or beryllium), and also by coldrolled alloys (‘structural hardening’). Known to watchmakers as ‘white metal’ springs (as opposed to blued carbon steel), these are stainless and have a higher elastic limit. They are less subject to permanent bending (becoming tired’) and there is scarcely any risk of their breaking. Some of them are also practically non-magnetic.

In their relaxed form, mainsprings are made in three distinct shapes:

  • Spiral coiled: These are coiled in the same direction throughout, in a simple spiral.
  • Semi-reverse: The outer end of the spring is coiled in the reverse direction for less than one turn (less than 360°).
  • Reverse (resilient): the outer end of the spring is coiled in the reverse direction for one or more turns (exceeding 360°).

The semi-reverse and reverse types provide extra force at the end of the running period, when the spring is almost out of energy, in order to keep the timepiece running at a constant rate to the end

he mainspring is coiled around an axle called the arbor, with the inner end hooked to it. In many clocks, the outer end is attached to a stationary post. The spring is wound up by turning the arbor, and after winding its force turns the arbor the other way to run the clock. The disadvantage of this open spring arrangement is that while the mainspring is being wound, its drive force is removed from the clock movement, so the clock may stop. This type is often used on alarm clocks, music boxes and kitchen timers where it doesn’t matter if the mechanism stops while winding. The winding mechanism always has a ratchet attached, with a pawl (called by clockmakers the click) to prevent the spring from unwinding.

In the form used in modern watches, called the going barrel, the mainspring is coiled around an arbor and enclosed inside a cylindrical box called the barrel which is free to turn. The spring is attached to the arbor at its inner end, and to the barrel at its outer end. The attachments are small hooks or tabs, which the spring is hooked to by square holes in its ends, so it can be easily replaced.

The mainspring is wound by turning the arbor, but drives the watch movement by the barrel; this arrangement allows the spring to continue powering the watch while it is being wound. Winding the watch turns the arbor, which tightens the mainspring, wrapping it closer around the arbor. The arbor has a ratchet attached to it, with a click to prevent the spring from turning the arbor backward and unwinding. After winding, the arbor is stationary and the pull of the mainspring turns the barrel, which has a ring of gear teeth around it. This meshes with one of the clocks gears, usually the center wheel pinion and drives the wheel train. The barrel usually rotates once every 8 hours, so the common 40-hour spring requires 5 turns to unwind completely.

Half-inch, Oil-tempered Compression Spring

Tuesday, August 7th, 2018

This week’s Katy Spring capability features a half-inch, oil-tempered compression spring, used in the agriculture industry.
Larger springs like these, weighing four-and-a-half pounds each, are stress relieved in large batch ovens.
Heavy-duty wire baskets, like the ones shown in this photograph, are loaded by hand and put into the oven with a forklift.
These heavier springs are too large and require longer baking times to be stressed relieved in an inline oven. | 281-391-1888

half-inch, oil-tempered compression spring,

half-inch, oil-tempered compression spring,