Mechanical Engineering Students

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Yellow Tag Tool Manual

Safety Equipment Available for All Users

  • Safety Glasses (3 times per quarter after that, you must supply your own.)
  • Face Shields
  • Welding Glasses/Goggles/Face Shields
  • Gloves
  • Ear Plugs/Ear Muffs
  • Dust and Particle Masks

Yellow Tag User Policies

  • Obtain tool-specific instructions when needed.
  • Wear Yellow Tag visibly at all times!
  • Wear safety glasses all the time while in the building.
  • Use personal protective equipment when required.
  • Have set-ups checked by a technician before beginning an observation.
  • Ask questions if in doubt about safety or operations or are unfamiliar with a tool.
  • Observe or do welding only while wearing eye protection of the proper shade, or observe through the tinted curtains.
  • Check in with a valid Cal Poly Student ID.
  • A minimum of 10 hours of Red Tag shop use must be recorded.

In addition to Red Tag tools, Yellow tag users may use the following hand and power tools (subject to the technicians' discretion) if they have taken and passed the Yellow Tag Safety Test:

Tools and Equipment

  • MIG and TIG Welders (Shade 10 eye protection required)
  • Oxy-Acetylene Rig (Shade 5 eye protection required)
  • Plasma Cutter (Shade 5 eye protection required)
  • Paint Booth and Gun (Respirator required)
  • Ovens (Composite/Heat Treating)
  • Mills
  • Lathes

Yellow Tag Tool Safety

General Safety

  • Yellow Tag users must always wear Safety Glasses while they are in the fenced shop area.
  • You must abide by all shop procedures and safety rules.
  • Wear your Yellow Tag so it is visible at all times!
  • If you don’t know how to use a tool, or don’t remember, ask a Shop Tech.
  • Wear appropriate clothing and Personal Protective Equipment for the job.
  • Clean grease and oil from hands before using tools to prevent slipping.
  • To prevent injury or damage to your project use only tools that are in good condition.
  • If you break a tool, stop using it and return it to a Shop Tech, (We won’t penalize you for accidental breakage, but we WILL penalize you for hiding the problem and compromising other people's safety.)
  • Report any unsafe behavior to a Shop Tech.
  • Report any spills to a Shop Tech.
  • Immediately report all injuries, no matter how minor, to a Shop Tech.

Specific Equipment Safety

Welding Equipment

  • For assistance in setting up the welding equipment ask a Tech.
  • Wear the proper shade of eye protection for the process that you observe-ask if in doubt! Shade 5 is for brazing, Oxy-Acetylene welding, flame cutting or Plasma cutting. Shade 10 is for MIG and TIG welding.
  • Protect your skin from the UV radiation of the arc. Wear long sleeves, gloves, etc.
  • Protect others from being exposed to the arc with the welding screens.
  • Quench hot materials in water or oil or mark them with the word “HOT” if air- cooling. Pass your hand above materials to check if they’re HOT before you touch them.
  • Do all welding in the welding area if at all possible. Shields and fire hazard precautions will need special attention if welding in other areas.
  • Check for adequate ventilation before welding.
  • Welding on zinc plated (galvanized) metals is hazardous to your health (it makes a POISON GAS) and can be fatal. NEVER weld on zinc plated metal, painted or coated materials!

Gas (Oxy-Acetylene) Welding

  • Gas cylinders must always be secured to a solid structure with a chain or other suitable device as a protection against falling or rolling.
  • Keep the welding equipment free of oil and grease, and away from oily rags. When oil comes in contact with oxygen it will explode!
  • Check for adequate ventilation before welding.
  • Keep ALL flammable material away from the work area.
  • Wear the appropriate welding goggles (shade 5) and gloves. Assistants and observers must also wear shade 5 welding goggles.
  • Release the regulator pressure screw and open the cylinders slowly.
  • If leaks are detected in the equipment, shut all valves off and report it immediately to a Tech.
  • Open the acetylene cylinder 1/2 turn maximum.
  • The normal pressure setting for acetylene is 5 p.s.i. with a maximum of 15 p.s.i. Acetylene explodes above 15 p.s.i.!
  • The oxygen cylinder valve should be opened all the way as it is a double seating valve.
  • The normal pressure setting for oxygen is 10 p.s.i. with higher settings used for torch cutting. (Ask for assistance when flame cutting with the torch.)
  • Point the torch away from yourself and observers before lighting it.
  • Use a friction torch lighter (flint striker) to ignite the torch.
  • Close the acetylene valve first if the torch backfires.
  • Keep sparks and flames away from the gas cylinders and hoses.
  • Never roll equipment over hoses or cords!
  • Close both cylinder valves and then release the pressure from the lines when you have finished the job.

Arc (Electric) Welding

  • Adequate ventilation is needed in the welding area before beginning.
  • Keep ALL flammable material away from the work area.
  • Never roll equipment over hoses or cords!
  • Wear the appropriate welding helmet (shade 10), long sleeves or leather apron, long pants and leather gloves (or cotton gloves if TIG welding).
  • Assistants and observers must also wear shade 10 welding helmets. These are required to protect the welder and observers from eye and skin damage by the intense ultraviolet (UV) radiation that emanates from the arc.
  • You are responsible for setting up the welding shields to protect others from the effects of the arcs’ UV radiation on their eyes and skin before you begin welding. The shields are to be erected across the entrance to the welding area if the welding is being done in the welding area. If the work piece cannot be brought into the welding area then the shields must completely encircle the welding being done.
  • Welding on zinc plated (galvanized) metals is hazardous to your health (it’s a POISON) and can be fatal. NEVER weld on zinc-plated metal or on painted materials!

MIG Welding

Metal, Inert Gas. Uses a "wire feed" and an Argon/CO2 gas mix.

  • Turn on gas to proper flow rate and set machine according to chart on inside of side cover.
  • Check the amount of wire on the wire spool before welding.

TIG Welding

Tungsten, Inert Gas. Uses a non-consumable tungsten electrode and an Argon inert gas with a water-cooled torch.

  • Turn on gas to proper flow rate and set machine according to a technician's instructions.
  • Make sure the torch coolant pump is full and running.

Plasma Cutter

  • Check for adequate ventilation before welding.
  • Keep ALL flammable material away from the work area.
  • Never roll equipment over hoses or cords!
  • Wear the appropriate welding goggles (shade 5) and gloves. Assistants and observers must also wear shade 5 welding goggles.
  • You are responsible for closing the welding curtains to protect others from the effects of the plasmas’ UV radiation on their eyes and skin before you begin the cutting process.
  • Plasma or Flame Cutting on zinc plated (galvanized) metals is hazardous to your health (it’s a POISON) and can be fatal. NEVER cut zinc plated metal or painted materials!

Spray Painting

  • Submit a detailed written report on the process you wish to do well in advance of using the Spray Booth.
    • Include MSDS’s (Material Safety Data Sheets), and the types of respiratory and exposure protection you intend to use.
    • Show your actual Personal Protection Equipment (PPE) to a Tech prior to using it.
    • Include Haz-Mat disposal procedures for all generated waste.
  • You must supply your own spray gun (HVLP preferred) when utilizing catalyst-type materials that harden due to chemical reactions.
  • All equipment must be thoroughly cleaned, or you will be charged for clean-up or replacement by the Mechanical Engineering Department.
  • Provide MSDS’s on all the materials being used to your instructor or advisor and the Techs well in advance of use (before you purchase it.)

Ovens (Composite/Heat Treating)

  • Get Tech approval before using the ovens.
  • Avoid flammable or smoke producing materials.
  • Provide a detailed written report on the process you wish to do well in advance of using ovens.
  • Provide MSDS’s on all the materials being used to your instructor or advisor and the Techs well in advance of use (before you purchase it.)

Machine Tools

Lathe

  • Roll up loose sleeves and do not wear loose clothes such as sweaters, jackets with strings or neckties while operating the lathe.
  • Be certain the work piece is set up securely and tightly when using chucks and collets.
  • REMOVE THE CHUCK KEY immediately after each use! If the lathe where accidentally activated while the chuck key was still in the chuck, the key could fly out and possibly cause serious injury or stay in and cause severe damage to the lathe.
  • After you have chucked up your work piece and completed your tool setup, you must spin the chuck by hand to ensure that the jaws of the chuck and the work piece will not hit the carriage of the lathe or the tool rest.
  • Keep hands on the controls or at your side while the lathe is running.
  • Keep hands away from chips as they are very sharp and possibly hot.
  • Complete cuts that are close to the chuck or against a shoulder by hand feeding to prevent machinery or work piece damage.
  • Remove the tool holder and tool post before filing or polishing. use only files with handles on the "tangs."
  • Never move the speed selector controls while the spindle is rotating.
  • Never push the reverse switch while a chuck is moving forward as this could cause the chuck to unscrew itself and fall off and cause serious injury.
  • Regulate the depth of a cut and the machine speed according to the size and type of material. Chips should look like the number "9."
  • If metal chips are wire-shaped, long and stringy, you should take a deeper cut and use a courser feed.
  • Never try to remove a mass of chips while the machine is running. They can cause loss of fingers or pull you into the machine!
  • Use tools that are properly ground for the particular job
  • You may never check measurements or surface finishes of the work piece while it is spinning.
  • When you do Between Centers Turning:
    • Use the safety dog to drive work piece
    • Clamp the tailstock securely.
    • Use only a live center.
  • When you do a Chuck and Faceplate Turning:
    • Counterbalance work piece on the faceplate if it is irregular in shape.
    • Stand away from the revolving faceplate to avoid being hit by flying objects.

Milling Machine

  • The milling machine is a precision piece of equipment. Its table is not a workbench or a place to put tools.
  • Keep hands away from chips as they are very sharp and possibly hot.
  • Keep hands on the controls or at your side while the mill is running.
  • Roll up loose sleeves and do not wear loose clothes such as sweaters, jackets with strings, or neckties while operating the mill.
  • Secure the work piece firmly in the vice or with appropriate claps.
  • Hold round stock securely with a "vee block" in a vise.
  • Be certain both the work piece and the tool are set up securely and tightly when using vises, chucks, and collets.
  • Remove all chuck keys and wrenches from the Quill or from tooling immediately after each use! If the mill were accidentally activated while the chuck key or wrench as still in the chuck or tooling, it could fly out and possibly cause serious injury or stay in and cause severe damage to the mill.
  • Be sure you know how to use the switch and brake to stop the milling machine quickly before operating the machine.
  • Be sure the power feed controls are in their "neutral" position BEFORE turning on the machine.
  • Handle cutters carefully. They are sharp and can easily cut you.
  • Use a soft hammer or mallet to seat the work piece against the parallel bars or bottom of the vice.
  • Check the work piece, milling machine table, and holding device for clearance of the quill during the cutting.
  • Set the machine for the proper depth of cut.
  • Select the correct spindle speed for the type of material and the cutter being used.
  • Select the proper direction of rotation for the cutter.
  • Feed the work piece against or opposite the direction of rotation of the cutter.
  • Never try to feel the finished surface while the cut is being taken with the mill.
  • Always wear a face shield when performing fly-cutting operations.
  • Regulate the depth of cut and the machine speed according to the size and type of material. Chips should look like a number "9."
  • If metal chips are wire-shaped, long, and stringy, you should take a deeper cut and use a coarser feed.
  • Never try to remove a mass of chips while the machine is running. They can cause loss of fingers or pull you into the machine!

Read the Shop Rules and Regulations prior to arriving for a tour.